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Our chemistry teacher taught us a great way to remember the difference between Solutes, Solvents and Solutions. 'Solute is what you put; Solvent is where it went; and Solution is what you're producing' Hope that helped anybody! :)
I work in a hospital, we use hydrogen peroxide to clean particularly stubborn instruments where the blood just won't get out. It's fun to watch it bubble like mad (oxidizing reaction from interacting with catalase). Also good at removing stains on plastic parts from surgical prep solutions
I would really like to thank you for Crash Course Chemistry, it is really helping me through high school, I really enjoy science, but chemistry is really hard for me to understand, because its makeup is so small and how it works in such a big way... it just really hurts my head sometimes, and thanks to you, I can actually understand it. All of the Crash Course playlists are amazing, thank you Hank, and John Green both for making these Crash Course videos!
At 9:50, molality=moles of solute/Kg of solution. Instead, it should be: molality=moles of solute/Kg of solvent. The mass of the solution and the mass of the solvent are two very different values.
I absolutely love how they do a background on some of the great discoveries of chemistry. I pretty much do this this stuff for a living and I have never learned who the Arrhenius is in the Arrhenius equation or Avogadro in Avogadro's constant until this show. Amazing.
As a pharmacist, %w/v is actually really useful. Allows us to work out how much drug there is in a volume of liquid which helps with dosing up little kids :p
Without crashcourse I would have lost my mind by now. I'm a history and language nerd, so chemistry is my archenemy. Because of this video I now longer am panicking about my next test, and so I thank everyone who works on these videos for helping me and my lab group not only get through high school but move on to hopefully be a teacher myself (though of course not a teacher of chemistry).
Yes, 430ml, IF you accept that you need only 0,01 molar solution to clean and not dissolve shirts. Because Hank don't show where he got the molar solution 2.
Ditto to caleb fisher's comment. Molality is moles of solute divided by kilograms of SOLVENT. Actually, for most solutions where we care about colligative properties (one of the main reasons for using molality) the results of the math come out almost the same but we chemistry teachers are soooooo picky aren't weeeee! I do, never-the-less, love your chemistry videos. I use them in my classes quite a lot. Keep up the good work!
bruh, thanks for making these. I have an awesome Chemistry professor but she skips a lot of material. These crash course videos really help me fill in the missing links.
10:23 yeah, dude, measuring solutions in percentage might not make sense to chemists, but it's the way to go in medicine. We dispense drugs in doses, meaning we just need to know the mass of the drug we're giving - the solution it's in is often secondary. If we'd have to figure out dosage from a liquid's molarity' rather than percentage, a lot more people would die in hospitals...
I've been using these videos for my chem notes. It's makes way more sense than my textbook and my teacher, I just have to pause a lot; thanks #crashcoursechemistry!
+Hanneli Seirrah yeah.... It's equally as fun to remember as the difference between "Mitosis" and "Myosis". Apparently the people who decide this stuff can't make the frigging words for the differences more distinct than the difference between a vowel-sound and a consonant sound >:( What would be wrong with "SexSplit" and "BodySplit" or something clear like that?
Hi there! Huge fan of Crash Course, and interested in learning Chemistry. I eat CC Psychology episodes like candy. Digest CC Mythology for fun. CC Philosophy is one of my guilty pleasures. You guys do a GREAT job. Buuut... I'm finding it hard to understand CC Chemistry. It moves too quickly, and doesn't include enough labeling in the visual examples to follow what everything is, when showing processes or patterns. A whole episode on ions wouldn't be a bad idea, for an idea of how pacing could be easier to follow. Again, huge fan! I would love to see a CC Chemistry 2.0 Thank you for all you do
The fact that you have taught me both interesting chemistry and how get my laundry cleaner without bleach..... There are no words. Thank you so much, Hank. Your object lesson applies directly to my life! :D
***** Of course it does, just a lot less now, well mostly (there was that one scientist that helped land a probe on an asteroid and he was ridiculed and attacked by feminists because he wore a shirt with hot chicks on it)
Nate G he was criticized for that shirt because it was highly inappropriate and in pretty much any workplace he'd be major trouble with his boss, or even fired. when discussing something highly important in your work environment, you'd probably want to dress very nicely and not wear a shirt with half naked women on it that distracts your audience from the hard work you have done.
Molly Name Wow and to go so far as to completely destroy one of the greatest achievements in this guy's life so far just because he has a casual shirt on? Besides being fired for wearing an "inappropriate" shirt on the wrong day when he had just landed a fucking probe on an asteroid would be really stupid to begin with. Also that wasn't just criticism that was a public shaming that completely over clocked this amazing achievement and made it seem like it doesn't matter because *gasp* he's wearing a shirt he likes but somehow offends someone else.
Nate G literally tell me what job you wouldn't be fired or at least reprimanded for wearing a shirt as inappropriate as that to present such great discoveries to a worldwide audience
Molly Name Actually I remember reading that his colleagues didn't give two shits what he was wearing they saw him in that shirt and did not reprimand him or get mad at him, please if they cared about what he was wearing they would have put another scientist to do the press conference or whatever and no he did not get reprimanded the only negative backlash (from what I could remember) was from a bunch of butthurt women and misguided feminists.
I've been taught to work in litres in school and university. Obviously if that's what's required for A-Level use dm^3, but if you were to go further with Chemistry you would find litres are used. The SI unit of volume is m^3 but SI units aren't always standard in different areas of science. For example Chemistry also uses grams instead of the SI kg for mass. It most often depends on what is most convenient for that particular field of research.
Oh my god I'm s happy we watched this in my science class and I was like yeasssss it's hank! And everyone was like, why is he talking so fast ? It was so awesome :D
I have a test tomorrow on this topic and this video helped me more then a book could have. It's fast-paced, yet simple and clear. So thanks! I'm a big scishow fan BTW.
Also, % weight by volume is absolutely one of the most common ways of describing solutions in chemistry. If someone says "x% solution", they mean percent weight by volume. And lots and lots and lots of solutions are described that way
It's mostly a solution, but there might be some suspended stuff. The sugar is dissolved, as is the caffeine, and the tannins, and whatever other vitamins which might be present. On the other hand, if you add milk to your tea, then the fat in the milk occurs in the form of the suspension (since it doesn't dissolve, for reasons stated in the videos).
If a molecule's(like salt's) solubility in water leads to dissociation between the molecule's cations and anions, then how is it still the same substance as before? Wouldn't that make it into a different thing all together? I mean, salt still tastes like salt when you dissolve it in water.
Syne the Sage yup, our salt-tasting cells are sensors for simple anions like sodium ions (but not hydrogen ions, which are what our sour receptors sense).
2:38 Just a note for all of you guys-- this statement isn't correct, solvents & solutes can both be any state of matter. Anyway great episode as always, I love crash course
Pure water does conduct electricity due to the ionization/de-ionization cycle Hank :-) i.e. there are always a certain amount OH (Hydroxide) and OH3 (Hydronium) ions present, approx. (concentration) 1 x 10-7 M each respectively present in pH neutral water - hence pH7. Pure H2O (theoretical) would not conduct elec. I suppose, as it has no free electrons - but good luck finding that! As you say water is such a great solvent. Thanks for the great classes, awesome! (Personally I see water more as a fundamental force of nature anyway) ;-)
Use other sources as well. Crash Course gives maximum benefits only to those who have a good foundation on the subject. Otherwise, we'd be drowning in all the information, just as we are right now. :P
+Pragya Sahay Molality is a property of a solution and is defined as the number of moles of solute per kilogram of solvent. Just do a simple search before you try and correct someone. Google -> Molality -> sorted. Easy :)
O2 is already a polyatomic ion known as Peroxide. It has a charge of -2. To balance out this charge it bonds with 2 hydrogen atoms. H202 is named Hydrogen Peroxide because of the way you're supposed to name ionic compounds (no prefixes). Hydrogen + Peroxide becomes Hydrogen Peroxide. Water on the other hand is a covalent bond that is not created through charge. It is named with prefixes.
Yes that'd make the water taste salty, yes that'll make chlorine gas (and some other stuff - there is normally bleach in pool chlorine), not really in such low concentration - but don't go inhaling a pool worth of evaporated water or snorting the pool chlorine directly - that will probably kill you. Yes sodium reacts explosively, no explosion because salt isn't pure sodium - it's a different compound with a different set of chemical (and reactive) properties.
+AlbinosaurusR3X Sadly Crash Course doesn't allow for that same kind of silly charisma; it's better for more quick and dry humor to keep information flowing and get the concepts as deep as possible in a 10-15 minute video. Quick and dry humor doesn't usually work well with kids, but with late tweens, teens, and many adults.
+AlbinosaurusR3X Sadly Crash Course doesn't allow for that same kind of silly charisma; it's better for more quick and dry humor to keep information flowing and get the concepts as deep as possible in a 10-15 minute video. Quick and dry humor doesn't usually work well with kids, but with late tweens, teens, and many adults.
A stabled atom has the amount of electrons equal to the amount of protons. When an atom has an excess amount of electrons (we call this atom an ion then), the ion is an anion (negative charge). When there are less electron than it's supposed to carry, we got a cation (positive charge). Electrolytes is the substance containing ions when is dissociated by the addition of a solvent or heating. Example: NaCl is an electrolyte bc when you add water it turns in Na+ (positive charge) and Cl- (negative)
Is it possible you could write out your division equations on top of one another? It's difficult to follow when it's all strung together left to right, a full dimensional analysis-type setup would be waaaay more helpful. Thanks for the video!
Make video on coordination compounds please!! Your videos really made me score more!!! I got a hundred marks more on my last exam which is actually for 720 . I got 500 due to your videos . Even the toppers get only300.
It''s not about the chemistry, it's about the safety. Combining strong acids with water (whichever way you do it) can generate heat. In some cases, it can generate enough heat to boil and splash. If it does this, it's better to be splashed with a bit of added acid in mostly water, rather than a bit of water in mostly acid. From personal experience, concentrated Sulfuric Acid gets very hot when mixed with water. Also, it'll also burn paper, which is interesting to watch.
Just out of curiosity, is any1 here just because they genuinely enjoy learning about chemistry in their free time and aren't studying for school? Like, their other subjects I can understand. Physics is weirdly wonderful in that it has lots of counter-intuitive things like general relativity and quantum mechanics. Philosophy (or, to b more specific, God) is always an interesting topic of conversation. So is politics (which's also important, if u want some idea of how 2 vote) and economics is a somewhat controversial (yet all the more interesting because of it) subject to be educated about (especially since it sort of links back to politics), which's y I keep up 2 date on those videos of theirs (still waiting for that modern physics tho!) However... I have never met any1 hu is just interested in chemistry and wud go out of zer way 2 learn it. At least, not as much as those other subjects I just mentioned.
its an intimidating subject, and unlike politics, philosophy, and economics, it's one that you can't really get deep into without experimenting and gaining first hand experience in a classroom or lab. You can talk with your friends all day about the meaning of life, but you can't really study chemical reactions just for fun, because for one, the equipment isn't readily available, and two, it takes a lot of studying just to be able to conceptualize what is really happening. Its an invisible science mostly, and people don't find what they can't easily understand or even experience to be very engaging . I think if more people really dedicated just a little bit of energy to see what chemistry can show us beyond just equation balancing and a periodic table, they would see how amazing the science really is. But you kinda have to go to school to get that basic and necessary understanding
I'm currently restraining myself from buying a set of lab glassware off ebay. loads of of the fun bits for 85 uk £. i've no idea what i'd do with it but i want it.
The end of the video confused me a little. When you do the math to calculate initial volume it is: (M2*V2)/M1 = V1 which if you plug the numbers in is: (0.01*38)/0.88 = 0.43 mol/L. Somebody tell me where I went wrong.
I absolutely love all of your crash course videos! I adore learning about science, but find it incredibly difficult to follow in class. These videos are perfect! Thank you!!!
HEY, here is a mistake !! Molality is m= moles of a solute/ kg of a solvent , you may put a corection , you made me doubt for my exam , really like CrashCourse :D
"All truth passes through three stages: First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as self-evident." - Arthur Schopenhauer
Hank is simplifying. This is a redox process. In order for the reaction of H2O2 -> H2O + O- to occur, it needs to gain an electron from something. so the actual equation should read e- + H2O2 -> H2O + O-, but this is only a half reaction because reduction never occurs without oxidation.
Where were you when i was in high school hank! ?! (Prob in primary school... sigh). This crash course stuff is brilliant! My 15yo daughter is struggling with stoich and im keen for her to look at this and hopefully capture some of your infectious enthusiasm... as someone who was a scientist, but who was generally terrible at maths, stoich was the only maths that made any sense to me... and i guess i wouldnt have been much use in the lab without it ;) All power to you and the sci show folk... with so much negativity and criticism dispensed on social media i just wanted to send you guys a positive message of encouragement... great stuff and thanks for all you do! Cheers, Jon (Melbourne, Australia).
Overall, this was a really good episode...but I feel the need to point out that a solvent doesn't have to be a liquid. It can be a gas or a solid too. A solution can be a mixture of solids or gases or whatever. The only thing that determines the solvent is the amount of the substance. Whichever substance you have more of - that's the solvent.
when a salt is dissolved it like a plazma when conducting electricity... however each individual ion kinda wants to form an acid or a base that it could have come from. That means that it will search for a H+ or an OH- (assuming your solvent is water), and if it is more stable to form this, then this will happen (by a ratio of how much more stable it is). you can go the other way and apply le chat's principal and screw up acids and bases ability to become electrolytes by having ions present.
No ones doing actual calculations.. the M1 is wronggg.. its .432 L or 432 mL.... Unless my calculator is broken, which i doubt. Im sorry Hank, your clothes will still be dirty after yo tea..
your calculator is not broken, you just switched the numbers when dividing (38/0.88 instead of 0.88/38) which works out to 43.18 and then multiplied by 0.01 to get your figure of 0.432L. The equation will work out if you divide the moles into the liters.
1. They have Crash Course History and Literature. 2. I've seen those channels already, and they hardly ever mention it, at least not in the videos I've seen. 3. I've tried searching for calculus videos. Most of the ones I've watched say "and you can see the rest of the videos if you sign up for this course on our website and pay..." you get the idea.
When salts are separated into their ions in water, how do those ions not react with the water? Sodium and water create an explosion; so how do the sodium ions not react with the water surrounding them in the same way?
because if you throw sodium into water,the sodium ATOMS will violently react with the water molecules because they're "unsatisfied". However, sodium ions are "satisfied" and don't "want" to react, because they're energeticly stable
Theoretically, you're right - the math doesn't care which you add to which. Practically, however, you present a safety hazard when you add water to acid. A reaction can produce heat which will cause bubbles that lead to splashes. Since the reaction occurs in the container that you are pouring into, it's better to have water in that container. It all comes down to if you'd rather get splashed with HCl and a bit of water or water with a bit of HCl? tl;dnr - Do what you otter, add acid to water
FishCakeIce Seriously, we're all now living in a microwave oven called EMF transmissions reflecting inside the magnetosphere. Yes, we're being overly-dehydrated because of the crazy positive-charge we all now experience. It's literally harder to come by electrons in 2015 compared to 1915. Energy is conserved, so it's not that water is creating electrons, but that water running over sunlit rocks adds electrons to the water (or you just raise the pH to increase the electrons). This is why reverse osmosis water is a huge thing now because it has way more electrons in it, delivering it into our bodies. The human body is desired to have a net Negative charge, so the more Positive you make it (closer to a net Neutral charge), the more inflammation you get, the more disease, more problems with the neurology in particular. Grounding helps a bit to replenish electrons too, but yes, it's mostly the water and the retention of the electrons and making use of them across the mitrochondria due to DHA in the diet. Eat a lot of seafood and drink a lot of water and most diseases go away if you're semi-healthy already. If you have deeper issues, there's more types of therapies that also help to add more electrons like Cold Thermogenesis and Blue-light blocking. Do some reading on the Photoelectric Effect (Einstein).
FishCakeIce As an interesting side-note on this, everything we excrete form the body (urine, #2, sweat and even from the lungs) is more positively charged than our net negative-charge in our bodies. So we're literally peeing out more protons while consuming electrons to keep an overall negative charge.
This may be very simple-minded of me but I'm still very interested in seeing how hydrogen peroxide can be used a stain remover. Does it only work with whites or can you use it on colors too.
Diluting acid is an energy-releasing reaction (you can actually feel the new solution warm up as you add more acid). This means that if you were to add water to a concentrated acid, the great heat released would immediately boil the water splashing you with water and concentrated acid (ouch!). By adding acid to the water you allow the water molecules to slowly dissolve the acid and prevent it from splashing you.
I don't get the math at 11:54 together. I get this: 0.88 mol/L*V1=0.01 mol/L*38 L 0.88 mol/L*V1=0.38 mol 0.88 mol/L*V1/0.88 mol/L=0.38 mol/0.88 mol/L V1=0.43 L But he says 0.24 L? Can someone please explain?
+NICHOLAS CHAMBERS V1 is the amount of solution that Hank will be adding to his laundry and is the variable that we are trying to solve for . If he poured in the whole bottle, it would be 1 liter. However this would be too much H2O2 for his purposes. He gave us 0.01mol/liter as the ideal dilution of H2O2 to whiten socks and we know he will have 38 liters of water in his tub. So now we just need to find how much hydrogen peroxide to add to that 38L in order to get down to the proper dilution of 0.01mol/liter...which is apparently 0.43 liter. Hope that helps!
A question that I've never been clear on: When the component ions of a compound (say sodium chloride) are dissolved in water, to they retain their "sodium chloride-ness" or do they display the properties of the component ions? In other words, is salt still actually salt when it dissolves?
If only youtube had a setting of 0.9 speed. You're amazing Hank, but you talk a bit too fast for non natives (of english speaking) Anyway, keep it up and thank you
The chemistry seems good as far as I can tell, but the physics at 5.24 with the light bulb turning on makes me sad. No matter what is happening in the beaker, the circuit isn't completed in two ways so the light can't turn on . 1) Connect to both ends of the battery. 2) Connect to both the base and metal side of the light bulb.
percentage is an acceptable measure of concentration. When you divide the mass solute by the volume solvent, you get a fraction, and any fraction can be written as a percentage. It is just a different way to write it. I still prefer fractions though.
It's a shame I need to reproduce all this stuff in german... makes everything just a little bit more difficult.... but luckily I have found that most therms just literally translate... THANKS SCIENCE!!!
Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!
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Our chemistry teacher taught us a great way to remember the difference between Solutes, Solvents and Solutions.
'Solute is what you put;
Solvent is where it went;
and Solution is what you're producing'
Hope that helped anybody! :)
"I named my first cat ion."
Took me a full 30 secs to finally facepalm.
8Ansa hello from 2020
Hydron
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█▄▄ █▀█ ░█░ █ █▄█ █░▀█
I work in a hospital, we use hydrogen peroxide to clean particularly stubborn instruments where the blood just won't get out. It's fun to watch it bubble like mad (oxidizing reaction from interacting with catalase). Also good at removing stains on plastic parts from surgical prep solutions
I would really like to thank you for Crash Course Chemistry, it is really helping me through high school, I really enjoy science, but chemistry is really hard for me to understand, because its makeup is so small and how it works in such a big way... it just really hurts my head sometimes, and thanks to you, I can actually understand it. All of the Crash Course playlists are amazing, thank you Hank, and John Green both for making these Crash Course videos!
hey bro, did you ever pass high school
At 9:50, molality=moles of solute/Kg of solution. Instead, it should be: molality=moles of solute/Kg of solvent. The mass of the solution and the mass of the solvent are two very different values.
So what I'm hearing is, I don't need to buy energy drinks, I just need to dissolve some salt in water?
that basically all energy drinks are. water, dye, flavor, and salt.
Energy drinks usually have caffine in them. They're basically coffee soda.
hedgehog3180 Caffeine doesn't provide energy though. It blocks receptors that make you tired. The energy part is just a placebo
Pickle juice (AKA vinegar) is a great hydrator. Better than gatorade because you're not taking in massive doses of sugar at the same time.
Energy drinks are caffeinated, if you meant Gatorade then ya, add sugar salt and potassium salt. Best to just drink water though.
LOL 'I named my first cat ion.'
Im done XD
i have a cats named nuetron, proton, electron, and ion. if i ever get twin cats there names will be solute and solvent
cation
lol
even funnier when you know that ion in romanian is an actual name
Are you paw-sitive about that
@@favourak5144 i gus' so.
"it's good a killing things and that's why we use it in swimming pools"
Evan Knowles lmao, why didnt i see this 3 years ago
Evan Knowles well, I should stop going to the pool then shouldn’t I
Population control and hello from 2020
yet another way to die in a pool. whoopee.
u.u Time to go to the pool then
I absolutely love how they do a background on some of the great discoveries of chemistry. I pretty much do this this stuff for a living and I have never learned who the Arrhenius is in the Arrhenius equation or Avogadro in Avogadro's constant until this show. Amazing.
As a pharmacist, %w/v is actually really useful. Allows us to work out how much drug there is in a volume of liquid which helps with dosing up little kids :p
And you allways asume that is a percentage of ml in grams? I can't really get this
Without crashcourse I would have lost my mind by now. I'm a history and language nerd, so chemistry is my archenemy. Because of this video I now longer am panicking about my next test, and so I thank everyone who works on these videos for helping me and my lab group not only get through high school but move on to hopefully be a teacher myself (though of course not a teacher of chemistry).
We need more people like hewell these days. There are so many things that could use cooler names
It's not 0.24 liters of H202, it's 0,43 liters . Spent like an hour trying to figure out how to get 0,24 liters .
Oh thank god other people noticed this, I thought I had suddenly forgotten the rules of algebra or something
cannibis sativa
I think you are right
Yes, 430ml, IF you accept that you need only 0,01 molar solution to clean and not dissolve shirts. Because Hank don't show where he got the molar solution 2.
THANK YOU
thanks
Ditto to caleb fisher's comment. Molality is moles of solute divided by kilograms of SOLVENT. Actually, for most solutions where we care about colligative properties (one of the main reasons for using molality) the results of the math come out almost the same but we chemistry teachers are soooooo picky aren't weeeee!
I do, never-the-less, love your chemistry videos. I use them in my classes quite a lot. Keep up the good work!
Dude, I tip my hat to you. You have a video for everything I have needed so far in chemistry. Thanks for the help buddy :)
bruh, thanks for making these. I have an awesome Chemistry professor but she skips a lot of material. These crash course videos really help me fill in the missing links.
Tea is my aqueous solution to everything
+Duke Travers same
Duke Travers you must be a true Englishman
Yes lad i bet ye haven't had a good bit of sugar in it
10:23 yeah, dude, measuring solutions in percentage might not make sense to chemists, but it's the way to go in medicine. We dispense drugs in doses, meaning we just need to know the mass of the drug we're giving - the solution it's in is often secondary. If we'd have to figure out dosage from a liquid's molarity' rather than percentage, a lot more people would die in hospitals...
I've been using these videos for my chem notes. It's makes way more sense than my textbook and my teacher, I just have to pause a lot; thanks #crashcoursechemistry!
I love that there are are no spammers on crash course videos!
Hank, thank you .
This course gave me a better understanding of chemistry in fact, made me understand it
Molarity and molality? Oh my God, No...........
+Hanneli Seirrah lal
+Hanneli Seirrah ikr
+Hanneli Seirrah
yeah.... It's equally as fun to remember as the difference between "Mitosis" and "Myosis".
Apparently the people who decide this stuff can't make the frigging words for the differences more distinct than the difference between a vowel-sound and a consonant sound >:(
What would be wrong with "SexSplit" and "BodySplit" or something clear like that?
+SixSixSix scientists like to sound clever
lol ikr? well that's science 4 u... were just gonna have 2 learn 2 live with it...
(damn scientists...)
Whoa, why is Wall-E with mr. Faraday 5:50
+Kraized I was wondering that myself.
Hi there! Huge fan of Crash Course, and interested in learning Chemistry.
I eat CC Psychology episodes like candy. Digest CC Mythology for fun. CC Philosophy is one of my guilty pleasures. You guys do a GREAT job. Buuut...
I'm finding it hard to understand CC Chemistry. It moves too quickly, and doesn't include enough labeling in the visual examples to follow what everything is, when showing processes or patterns. A whole episode on ions wouldn't be a bad idea, for an idea of how pacing could be easier to follow.
Again, huge fan! I would love to see a CC Chemistry 2.0
Thank you for all you do
The fact that you have taught me both interesting chemistry and how get my laundry cleaner without bleach..... There are no words. Thank you so much, Hank. Your object lesson applies directly to my life! :D
12:20 is WRONG!!!
V1=(M2xV2)/M1
=(0.01x38)/0.88
=0.43L
Not 0.24L What's more is that 0.24L=240mL not 250ml
😳
Thank god. I was following along and thought I'd really screwed up my maths
🥰
Jesus, there are so many errors in these videos they have made. Correction annotations have been removed too.
@@tb2748 You are a believer in Jesus? When did you repent of your sins? I am a newly convert as well.
"You'll remember, I hope." Come on Hank, have more faith. What were we talking about again?
Hank you have just saved my chemistry grade and my sanity in more ways than you can ever know
So much thought in just the naming process. I have been underestimating science for its brilliance.
Damn there have been a lot of scientists shunned and ridiculed by their peers and seniors. Does this stuff still happen today?
***** Of course it does, just a lot less now, well mostly (there was that one scientist that helped land a probe on an asteroid and he was ridiculed and attacked by feminists because he wore a shirt with hot chicks on it)
Nate G he was criticized for that shirt because it was highly inappropriate and in pretty much any workplace he'd be major trouble with his boss, or even fired. when discussing something highly important in your work environment, you'd probably want to dress very nicely and not wear a shirt with half naked women on it that distracts your audience from the hard work you have done.
Molly Name Wow and to go so far as to completely destroy one of the greatest achievements in this guy's life so far just because he has a casual shirt on? Besides being fired for wearing an "inappropriate" shirt on the wrong day when he had just landed a fucking probe on an asteroid would be really stupid to begin with. Also that wasn't just criticism that was a public shaming that completely over clocked this amazing achievement and made it seem like it doesn't matter because *gasp* he's wearing a shirt he likes but somehow offends someone else.
Nate G literally tell me what job you wouldn't be fired or at least reprimanded for wearing a shirt as inappropriate as that to present such great discoveries to a worldwide audience
Molly Name Actually I remember reading that his colleagues didn't give two shits what he was wearing they saw him in that shirt and did not reprimand him or get mad at him, please if they cared about what he was wearing they would have put another scientist to do the press conference or whatever and no he did not get reprimanded the only negative backlash (from what I could remember) was from a bunch of butthurt women and misguided feminists.
I've been taught to work in litres in school and university. Obviously if that's what's required for A-Level use dm^3, but if you were to go further with Chemistry you would find litres are used. The SI unit of volume is m^3 but SI units aren't always standard in different areas of science. For example Chemistry also uses grams instead of the SI kg for mass. It most often depends on what is most convenient for that particular field of research.
Oh my god I'm s happy we watched this in my science class and I was like yeasssss it's hank! And everyone was like, why is he talking so fast ? It was so awesome :D
I have a test tomorrow on this topic and this video helped me more then a book could have. It's fast-paced, yet simple and clear. So thanks! I'm a big scishow fan BTW.
Also, % weight by volume is absolutely one of the most common ways of describing solutions in chemistry. If someone says "x% solution", they mean percent weight by volume. And lots and lots and lots of solutions are described that way
It's mostly a solution, but there might be some suspended stuff. The sugar is dissolved, as is the caffeine, and the tannins, and whatever other vitamins which might be present. On the other hand, if you add milk to your tea, then the fat in the milk occurs in the form of the suspension (since it doesn't dissolve, for reasons stated in the videos).
You might MIGHT have just helped me pass my GCSE Chemistry. Thank you.
This has been very helpful since I'm taking chem now. So a very huge THANK YOU goes out to you. :D
If a molecule's(like salt's) solubility in water leads to dissociation between the molecule's cations and anions, then how is it still the same substance as before? Wouldn't that make it into a different thing all together? I mean, salt still tastes like salt when you dissolve it in water.
Syne the Sage
yup, our salt-tasting cells are sensors for simple anions like sodium ions (but not hydrogen ions, which are what our sour receptors sense).
For myself and any others interested, to revise over and over again until it is mind-numbingly understood and memorized:
9:20, 10:33, 11:36
I need a crash course to understand this crash course xD
2:38 Just a note for all of you guys-- this statement isn't correct, solvents & solutes can both be any state of matter. Anyway great episode as always, I love crash course
Pure water does conduct electricity due to the ionization/de-ionization cycle Hank :-)
i.e. there are always a certain amount OH (Hydroxide) and OH3 (Hydronium) ions present, approx. (concentration) 1 x 10-7 M each respectively present in pH neutral water - hence pH7. Pure H2O (theoretical) would not conduct elec. I suppose, as it has no free electrons - but good luck finding that! As you say water is such a great solvent. Thanks for the great classes, awesome!
(Personally I see water more as a fundamental force of nature anyway) ;-)
This guy is HILARIOUS, still very smart and a great teacher! I'd buy this course
+Brandon Stout Good thing it's for free huh
I've done okay so far but this video is crazy. After watching it high 3 times. I'm still lost at Moles, Molar, Molarity formulas
Same
Use other sources as well. Crash Course gives maximum benefits only to those who have a good foundation on the subject. Otherwise, we'd be drowning in all the information, just as we are right now. :P
I so wish i had these videos last year instead of sitting in boring Honor's chemistry class.Hank is awesome.A lot more interesting!DFTBA! :)
V1=(0.01 mol/L * 38 L) / 0.88 mol/L
V1=0.38 mol/L / 0.88 mol/L
V1=0.43181
I got the same. Is Hank's math off? That's the second time that happened in this series. WTF Hank, you might want to ask Santa for a new calculator.
Yh, lol I got the same.
+Tirra Hargrow How do you round 430ml to 250ml? I think it's a plain ol' mistake.
Can you tell me where did he get the molarity of the diluted solution / M2? How did he calculate it to be 0.01?
he didn't calculate that, it was the desired molarity for a proper laundry solution
are you going to do an episode on equilibriums? i know it covers a lot, but these videos really are useful. almost like study cards.
He's like the Bill Nye of youtube. And for teenagers.
Okay jackie, stay away from corona
Excellent work! Best and most concise series imaginable.
Thanks for the equations SciShow,
Its helping me a lot in my physiology course in college... Keep up the great work.
These videos literally go perfectly in time with my chemistry class. its awesome.
Molality is NOT moles of solute per kg of solution. It is moles of solute per kg of SOLVENT. Probably a silly mistake by mr. hank
+Ahnaf Islam Actually, he is right because we are talking about the stuff in a whole SOLUTION and NOT in just the solvent
+Pragya Sahay yeah but molality is moles of solute over kg of solvent. Period. U can't change that
+Pragya Sahay Molality is a property of a solution and is defined as the number of moles of solute per kilogram of solvent.
Just do a simple search before you try and correct someone.
Google -> Molality
-> sorted. Easy :)
actually mr. hank was right
Molality can also be understood as ratio of solute to solvent, while molarity is the amount of solute in solution
O2 is already a polyatomic ion known as Peroxide. It has a charge of -2. To balance out this charge it bonds with 2 hydrogen atoms. H202 is named Hydrogen Peroxide because of the way you're supposed to name ionic compounds (no prefixes). Hydrogen + Peroxide becomes Hydrogen Peroxide. Water on the other hand is a covalent bond that is not created through charge. It is named with prefixes.
Anyone else notice Faraday with Wall-E?
yea, can someone explain that to meeeeeeee?@_@
I understand from the picture that Both Wall-E & Faraday are Geniuses who work with each other.
Yes that'd make the water taste salty, yes that'll make chlorine gas (and some other stuff - there is normally bleach in pool chlorine), not really in such low concentration - but don't go inhaling a pool worth of evaporated water or snorting the pool chlorine directly - that will probably kill you. Yes sodium reacts explosively, no explosion because salt isn't pure sodium - it's a different compound with a different set of chemical (and reactive) properties.
I think Hank might be the next Bill Nye. =)
Bill Nye the science guy!
+skelos gaming BILL! BILL! BILL! BILL!
Never ///:
+AlbinosaurusR3X Sadly Crash Course doesn't allow for that same kind of silly charisma; it's better for more quick and dry humor to keep information flowing and get the concepts as deep as possible in a 10-15 minute video. Quick and dry humor doesn't usually work well with kids, but with late tweens, teens, and many adults.
+AlbinosaurusR3X Sadly Crash Course doesn't allow for that same kind of silly charisma; it's better for more quick and dry humor to keep information flowing and get the concepts as deep as possible in a 10-15 minute video. Quick and dry humor doesn't usually work well with kids, but with late tweens, teens, and many adults.
Glad to see that Dihydrogen Monoxide awareness is still out there. Thanks Hank! -The founder of the Coalition to Ban DHMO.
Wait, but when H²O² breaks apart into H²O+O-
Why does the O- take up electrons when it is negatively charged?
A stabled atom has the amount of electrons equal to the amount of protons. When an atom has an excess amount of electrons (we call this atom an ion then), the ion is an anion (negative charge). When there are less electron than it's supposed to carry, we got a cation (positive charge). Electrolytes is the substance containing ions when is dissociated by the addition of a solvent or heating. Example: NaCl is an electrolyte bc when you add water it turns in Na+ (positive charge) and Cl- (negative)
Favorite Chemistry teacher.
Is it possible you could write out your division equations on top of one another? It's difficult to follow when it's all strung together left to right, a full dimensional analysis-type setup would be waaaay more helpful. Thanks for the video!
Make video on coordination compounds please!! Your videos really made me score more!!! I got a hundred marks more on my last exam which is actually for 720 . I got 500 due to your videos . Even the toppers get only300.
It''s not about the chemistry, it's about the safety. Combining strong acids with water (whichever way you do it) can generate heat. In some cases, it can generate enough heat to boil and splash. If it does this, it's better to be splashed with a bit of added acid in mostly water, rather than a bit of water in mostly acid.
From personal experience, concentrated Sulfuric Acid gets very hot when mixed with water. Also, it'll also burn paper, which is interesting to watch.
LOL, the dilution equation looks very similar to the conservation of momentum equation in physics! :D
I say this on every Hank video:
I love Hank Green so much!
Electrolytes, it's what plant's crave!
idiocracy
You should do at the end of every video, make a list of everything that's most important to study.
Just out of curiosity, is any1 here just because they genuinely enjoy learning about chemistry in their free time and aren't studying for school?
Like, their other subjects I can understand. Physics is weirdly wonderful in that it has lots of counter-intuitive things like general relativity and quantum mechanics. Philosophy (or, to b more specific, God) is always an interesting topic of conversation. So is politics (which's also important, if u want some idea of how 2 vote) and economics is a somewhat controversial (yet all the more interesting because of it) subject to be educated about (especially since it sort of links back to politics), which's y I keep up 2 date on those videos of theirs (still waiting for that modern physics tho!)
However... I have never met any1 hu is just interested in chemistry and wud go out of zer way 2 learn it. At least, not as much as those other subjects I just mentioned.
same here I'm just watching because I find it interesting and like learning and getting smarter
Alex Christensen 2 each their own I guess. Enjoy!
I am!
😀
its an intimidating subject, and unlike politics, philosophy, and economics, it's one that you can't really get deep into without experimenting and gaining first hand experience in a classroom or lab. You can talk with your friends all day about the meaning of life, but you can't really study chemical reactions just for fun, because for one, the equipment isn't readily available, and two, it takes a lot of studying just to be able to conceptualize what is really happening. Its an invisible science mostly, and people don't find what they can't easily understand or even experience to be very engaging . I think if more people really dedicated just a little bit of energy to see what chemistry can show us beyond just equation balancing and a periodic table, they would see how amazing the science really is. But you kinda have to go to school to get that basic and necessary understanding
I'm currently restraining myself from buying a set of lab glassware off ebay. loads of of the fun bits for 85 uk £.
i've no idea what i'd do with it but i want it.
I love John Green. The way he talks and explains is phenomenal.
Then you should go watch US History!
Noor Fatima This is Hank Green... His brother
The end of the video confused me a little. When you do the math to calculate initial volume it is: (M2*V2)/M1 = V1 which if you plug the numbers in is: (0.01*38)/0.88 = 0.43 mol/L. Somebody tell me where I went wrong.
I got the same answer, I don't understand!
I don't think you're wrong, many people got the same answer: 431ml
Daniel Mazzone yeah it's actually right it's 0.431 litres I think it's cause Hank didn't have the capacity for it in his measure😂
I thinn .43 is right that's what i kept getting on ny Nspire Cx Cas
I absolutely love all of your crash course videos! I adore learning about science, but find it incredibly difficult to follow in class. These videos are perfect!
Thank you!!!
HEY, here is a mistake !! Molality is m= moles of a solute/ kg of a solvent , you may put a corection , you made me doubt for my exam , really like CrashCourse :D
I enjoy writing copious notes from your videos. No seriously, without you I would not get this at all.
It is weird that on how many people were laughed at for being right. (e.g Wegener, and many of the people you mentioned in Chemistry)
Fraser Souris For each of these men who were laughed at when right, hundreds were laughed at and wrong.
James Loftus Wise Words
"All truth passes through three stages: First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as self-evident." - Arthur Schopenhauer
Hank is simplifying. This is a redox process. In order for the reaction of H2O2 -> H2O + O- to occur, it needs to gain an electron from something. so the actual equation should read e- + H2O2 -> H2O + O-, but this is only a half reaction because reduction never occurs without oxidation.
12:13
Sorry but the math didn't add up to me , when I tried to calculate it I got 0.431
(Am I wrong or something?)
Can someone give me an answer
Where were you when i was in high school hank! ?! (Prob in primary school... sigh). This crash course stuff is brilliant! My 15yo daughter is struggling with stoich and im keen for her to look at this and hopefully capture some of your infectious enthusiasm... as someone who was a scientist, but who was generally terrible at maths, stoich was the only maths that made any sense to me... and i guess i wouldnt have been much use in the lab without it ;)
All power to you and the sci show folk... with so much negativity and criticism dispensed on social media i just wanted to send you guys a positive message of encouragement... great stuff and thanks for all you do! Cheers, Jon (Melbourne, Australia).
12:01 "We need a zero point one molar solution". You forgot the second zero: should be "point zero one". Sry.
Can you please explain how did he find out M2? How did he get 0.01?? It is at the same timestamp that you quoted.
Overall, this was a really good episode...but I feel the need to point out that a solvent doesn't have to be a liquid. It can be a gas or a solid too. A solution can be a mixture of solids or gases or whatever. The only thing that determines the solvent is the amount of the substance. Whichever substance you have more of - that's the solvent.
Hey! You! Stop scrolling! Get back to learning!
when a salt is dissolved it like a plazma when conducting electricity... however each individual ion kinda wants to form an acid or a base that it could have come from.
That means that it will search for a H+ or an OH- (assuming your solvent is water), and if it is more stable to form this, then this will happen (by a ratio of how much more stable it is).
you can go the other way and apply le chat's principal and screw up acids and bases ability to become electrolytes by having ions present.
No ones doing actual calculations.. the M1 is wronggg.. its .432 L or 432 mL.... Unless my calculator is broken, which i doubt. Im sorry Hank, your clothes will still be dirty after yo tea..
your calculator is not broken, you just switched the numbers when dividing (38/0.88 instead of 0.88/38) which works out to 43.18 and then multiplied by 0.01 to get your figure of 0.432L. The equation will work out if you divide the moles into the liters.
DAVASAURUSREX Also Sig Figs!
1. They have Crash Course History and Literature.
2. I've seen those channels already, and they hardly ever mention it, at least not in the videos I've seen.
3. I've tried searching for calculus videos. Most of the ones I've watched say "and you can see the rest of the videos if you sign up for this course on our website and pay..." you get the idea.
When salts are separated into their ions in water, how do those ions not react with the water? Sodium and water create an explosion; so how do the sodium ions not react with the water surrounding them in the same way?
because if you throw sodium into water,the sodium ATOMS will violently react with the water molecules because they're "unsatisfied". However, sodium ions are "satisfied" and don't "want" to react, because they're energeticly stable
+neet meep Thanks mate ;)
+Artur Takhtaganov thank you for your answer I was confused about that too🙌
Artur Takhtaganov that's a great answer, thanks
Theoretically, you're right - the math doesn't care which you add to which. Practically, however, you present a safety hazard when you add water to acid. A reaction can produce heat which will cause bubbles that lead to splashes. Since the reaction occurs in the container that you are pouring into, it's better to have water in that container. It all comes down to if you'd rather get splashed with HCl and a bit of water or water with a bit of HCl?
tl;dnr - Do what you otter, add acid to water
so is one of the reasons we need to drink water because we need it to create electrolytes?
Laura Rentfro Tyndall i know but i mean water in the first place
i think water is more essential than gatorade
we drink more water than gatorade, i think?
!? human's have REALLY evolved
FishCakeIce Seriously, we're all now living in a microwave oven called EMF transmissions reflecting inside the magnetosphere. Yes, we're being overly-dehydrated because of the crazy positive-charge we all now experience. It's literally harder to come by electrons in 2015 compared to 1915. Energy is conserved, so it's not that water is creating electrons, but that water running over sunlit rocks adds electrons to the water (or you just raise the pH to increase the electrons). This is why reverse osmosis water is a huge thing now because it has way more electrons in it, delivering it into our bodies.
The human body is desired to have a net Negative charge, so the more Positive you make it (closer to a net Neutral charge), the more inflammation you get, the more disease, more problems with the neurology in particular. Grounding helps a bit to replenish electrons too, but yes, it's mostly the water and the retention of the electrons and making use of them across the mitrochondria due to DHA in the diet. Eat a lot of seafood and drink a lot of water and most diseases go away if you're semi-healthy already. If you have deeper issues, there's more types of therapies that also help to add more electrons like Cold Thermogenesis and Blue-light blocking. Do some reading on the Photoelectric Effect (Einstein).
FishCakeIce As an interesting side-note on this, everything we excrete form the body (urine, #2, sweat and even from the lungs) is more positively charged than our net negative-charge in our bodies. So we're literally peeing out more protons while consuming electrons to keep an overall negative charge.
This may be very simple-minded of me but I'm still very interested in seeing how hydrogen peroxide can be used a stain remover. Does it only work with whites or can you use it on colors too.
#bestchemistryteacherever
Diluting acid is an energy-releasing reaction (you can actually feel the new solution warm up as you add more acid). This means that if you were to add water to a concentrated acid, the great heat released would immediately boil the water splashing you with water and concentrated acid (ouch!). By adding acid to the water you allow the water molecules to slowly dissolve the acid and prevent it from splashing you.
I don't get the math at 11:54 together. I get this:
0.88 mol/L*V1=0.01 mol/L*38 L
0.88 mol/L*V1=0.38 mol
0.88 mol/L*V1/0.88 mol/L=0.38 mol/0.88 mol/L
V1=0.43 L
But he says 0.24 L? Can someone please explain?
It is WRONG
V1=(M2xV2)/M1
V1=(0.01x38)/0.88 = 0.43L
I thought I was becoming stupid
+NICHOLAS CHAMBERS V1 is the amount of solution that Hank will be adding to his laundry and is the variable that we are trying to solve for . If he poured in the whole bottle, it would be 1 liter. However this would be too much H2O2 for his purposes. He gave us 0.01mol/liter as the ideal dilution of H2O2 to whiten socks and we know he will have 38 liters of water in his tub. So now we just need to find how much hydrogen peroxide to add to that 38L in order to get down to the proper dilution of 0.01mol/liter...which is apparently 0.43 liter. Hope that helps!
I've got the same answer, I have a feeling they messed up the math in this video??
thank you!
LOL WallE Easter egg. Too cute
It's not 'molarity', it's 'morality'.
A question that I've never been clear on: When the component ions of a compound (say sodium chloride) are dissolved in water, to they retain their "sodium chloride-ness" or do they display the properties of the component ions? In other words, is salt still actually salt when it dissolves?
If only youtube had a setting of 0.9 speed.
You're amazing Hank, but you talk a bit too fast for non natives (of english speaking)
Anyway, keep it up and thank you
+João Matos Graça same here
Hey, I am non native too.
But after watching lot of video I got used to it, you will get too
you can, you just have to click on the word "custom" where you choose the speed
The chemistry seems good as far as I can tell, but the physics at 5.24 with the light bulb turning on makes me sad. No matter what is happening in the beaker, the circuit isn't completed in two ways so the light can't turn on . 1) Connect to both ends of the battery. 2) Connect to both the base and metal side of the light bulb.
much appreciated if you could add text transcripts for your videos!
U mean captions?
percentage is an acceptable measure of concentration. When you divide the mass solute by the volume solvent, you get a fraction, and any fraction can be written as a percentage. It is just a different way to write it. I still prefer fractions though.
It's a shame I need to reproduce all this stuff in german... makes everything just a little bit more difficult.... but luckily I have found that most therms just literally translate... THANKS SCIENCE!!!
At 9:53, the formula of molality must be moles of solute / kg of "solvent", not solution.