@hewitt_playhew big dawg, if I'm not mistaken, after calculating the Number of moles of both HCl and Mg(OH)2 you will then divide that by the coefficient in front of the substance in the balanced equation.. So since we got 1.5 mols for HCl we will then divide it by the mole ratio in front of HCl in the balanced equation which is 1.5÷2= 0.75 Same thing for Mg(OH)2, so that will be 2.4÷1=2.4 Then to conclude we compare the 2 numbers and the one with the smaller number is the limiting reagent. So since 0.75 < 2.4 that makes HCl the Limiting Reagent/Reactant
To the future viewers not sure why HCL is the limiting reactant and not Mg(OH)2 its because the ratio 2:1 means that for every 1 molecule of Mg(OH)2 used, 2 molecules of HCL gets used up, the HCL loses more molecules per molecule of Mg(OH)2. and the reason the ratio later stipulates 1.5 mol : 0.75 mol is because the (2:1) comparison is on the HCL (1.5 mol) (1/2 of 1.5 is 0.75). if you compared it vice versa it would be: 4.8 mol (HCL) : 2.4 mol (Mg(OH)2. took me a few rewatches to get it lol
Thank you Kevin! You are a life saver!! My teacher rushed through this whole topic and I knew nothing! I'm writing a practical tomorrow based on this and I'm confident I'll do well thanks to you !!!
to get which one is limiting devide the number of moles by the coefficient .e.g. for HCL: 1.5 moles/2= 0.75 for Mg(OH): 2.4moles/1= 2.4 therefore the one with small answer is limiting, in this case HCL is limiting
@shitsakisinokeri4938 firstly, get both of the moles of the different molecules, HCl and Mg(OH)2 secondly, divide the moles by each other thirdly, divide the MOLE RATIOS by each other fourthly, check whichever mole is less than the value of your mole ratio divided by each other and then that will be your limiting reagent. (this is my way to do it)
Hi Kevin😊. I loveee these vids, cant get enough of them 😍. I just have a quick question: At the time stamp of 10:51, we are calculating the pH of the FINAL SOLUTION. This is my understanding, initially, in the vessel we have Acid and Base. Then the 2 will react together to form salt and water. There will then be an excess reagent present. So altogether we have in the vessel: Excess base, water, and the salt ( that was formed from the acid base reaction). Now...when we calculating the pH, of the final solution we are only worried about the pH of the excess base with the water. What about the salt? And the pH it gives to the final solution? Why we ignoring the salt ? What happens to the salt ? Hope to hear soon 😣plz.
Hi Simrah, so yes a salt can affect the PH due to hydrolysis but this only if we have a weak acid or base to begin with as hydrolysis only happens when we have a weak acid or base. This is not something you would ever be tested on in one question like this.
Glad it has helped you! I am not sure when titrations will be released on TH-cam but you can sign up to my website course and then find titrations in the grade 11 acid base section. Sign up for free 7 day trial here: www.kevinmathandscience.com/7dayW
Hi you guys You might think you understood it I telling you repeat watching this atleast twice or more it will be more easier than you thought you understood it😭😭
Imagine we add the 2 solutions together into a big container. So the volume would be 9. Then the reaction takes place between the acid and the base. The acid gets completely destroyed. But the container volume remains 9.
My physics teacher didn't even explain this and this man explains it like its Lo.
Haha love it!!!
@@kevinmathsciencewe love you
@@kevinmathsciencequestion how is it that HCl is the limiting reactant it’s the part I’m not getting..
@hewitt_playhew big dawg, if I'm not mistaken, after calculating the Number of moles of both HCl and Mg(OH)2 you will then divide that by the coefficient in front of the substance in the balanced equation..
So since we got 1.5 mols for HCl we will then divide it by the mole ratio in front of HCl in the balanced equation which is 1.5÷2= 0.75
Same thing for Mg(OH)2, so that will be 2.4÷1=2.4
Then to conclude we compare the 2 numbers and the one with the smaller number is the limiting reagent.
So since 0.75 < 2.4 that makes HCl the Limiting Reagent/Reactant
@@Thab06 my dawg🤜🤛
Last minute exam prep with Kevin's vids are always a win! Thank you sir
Same boat mate
same page
bad advice this one chief
@WesleyHlatshwayo 😂 It worked for me tho lmao
To the future viewers not sure why HCL is the limiting reactant and not Mg(OH)2 its because the ratio 2:1 means that for every 1 molecule of Mg(OH)2 used, 2 molecules of HCL gets used up, the HCL loses more molecules per molecule of Mg(OH)2. and the reason the ratio later stipulates 1.5 mol : 0.75 mol is because the (2:1) comparison is on the HCL (1.5 mol) (1/2 of 1.5 is 0.75). if you compared it vice versa it would be: 4.8 mol (HCL) : 2.4 mol (Mg(OH)2. took me a few rewatches to get it lol
but obviously there is only 1.5 mol of HCL so the comparison has to be done on the reactant that will be used up. (HCL)
God bless you
thank you so much
Great explanation. Immaculate!
Thanks❤
You don’t understand how many lives you change and save ❤. Love you Kevin
Thank you Kevin! You are a life saver!! My teacher rushed through this whole topic and I knew nothing! I'm writing a practical tomorrow based on this and I'm confident I'll do well thanks to you !!!
haha I'm so glad i could help! Good luck!
If only i could meet KEVINMATHSCIENCE i moved from level 4 to 7 in Physical science in 2023 thanks to KEVINMATH SCIENCE YOU ROCK
Damn it's really possible
Wow 😳 finally I found this chapter so easy
Thanks for you ,sir may God grant you with may years to help others up coming learners🙏🦋
Thank you so much for these videos, sir.
We binge watching Kevin for Monday 😭we will all pull through.
to get which one is limiting devide the number of moles by the coefficient .e.g.
for HCL: 1.5 moles/2= 0.75
for Mg(OH): 2.4moles/1= 2.4
therefore the one with small answer is limiting, in this case HCL is limiting
Thanks❤❤❤
you deserve head
Hey Kevin. Since the HCl is at a 2:1 ratio of of Mg(OH)2. Wouldn't that mean that Mg(OH)2 Is the limiting factor???
I'm a bit confused there as well
same
😭that's y I'm scouting in the comments for an answer
@@quinn_libbyme too lol
I swear I think he made an error coz I did it both ways and still HCl is the limiting reactant there..
Hi Kevin, @8:45 isn't the limiting Reagent Mg(OH)2? Cuz mole ratin is 2HCl=1,5×2=3mols and 1Mg(oh)2...=2,4 mols?
ya it is
Top 1, you're the best Kevin
Hey Kevin, I don't understand why we chose HCL as the limiting reactant
me too he said use the ratio but now HCL becomes the largest and MG(OH)2 becomes the limiting reagent
@shitsakisinokeri4938
firstly, get both of the moles of the different molecules, HCl and Mg(OH)2
secondly, divide the moles by each other
thirdly, divide the MOLE RATIOS by each other
fourthly, check whichever mole is less than the value of your mole ratio divided by each other and then that will be your limiting reagent.
(this is my way to do it)
Hi Kevin😊. I loveee these vids, cant get enough of them 😍. I just have a quick question:
At the time stamp of 10:51, we are calculating the pH of the FINAL SOLUTION.
This is my understanding, initially, in the vessel we have Acid and Base.
Then the 2 will react together to form salt and water. There will then be an excess reagent present.
So altogether we have in the vessel: Excess base, water, and the salt ( that was formed from the acid base reaction).
Now...when we calculating the pH, of the final solution we are only worried about the pH of the excess base with the water.
What about the salt? And the pH it gives to the final solution? Why we ignoring the salt ? What happens to the salt ?
Hope to hear soon 😣plz.
Hi Simrah, so yes a salt can affect the PH due to hydrolysis but this only if we have a weak acid or base to begin with as hydrolysis only happens when we have a weak acid or base. This is not something you would ever be tested on in one question like this.
Didn't understand what was happening, how do you figure out which is limiting and how did you get 0.75 : 1.5? Do you half the volume?
Thank you for this
11:13 Kevins jokes crack me up😂
Yo u writing ngomso 😂😭
Hey Kevin. Sorry to be a bother but could you explain further or in a different way as to why mg being +2 and CI -1 makes it MgCI2
hey there...i have the same problem and have no idea how to figure it out...did you?
You basically just want to balance the positive and negative charges on each ion, so you need 2 Cl- to cancel out the 1 Mg+2
@@lucaslgswitch3577 thank you man🙏👍🏿
Cross multiply
Bro you goated!!!!!!!!!!!!!!
hey kevin , thanks alot for this video .really helped . can you plsss do titration calculations.
Glad it has helped you!
I am not sure when titrations will be released on TH-cam but you can sign up to my website course and then find titrations in the grade 11 acid base section.
Sign up for free 7 day trial here:
www.kevinmathandscience.com/7dayW
Sorry Sir Kevin, when we do limiting reactants do we not use the limiting reactant to calculate the Ph or do we just use the excess reactant. 6:28
Hi sir, when do we not add the volumes of the reactants? Or when do we add?
Pov: you're learning this the day before your exam because your teacher is terrible and your lazy af
Are we the same person? 😢
@@unbelievableinside246 if you're writing chemistry on Monday then we are 😭
Good luck 🤞
😢I'm that guy
Hi sir..on 13:38,why did you choose to find moles of hydroxide instead of magnesium?
Give Kevin his flowers💐
I thought i was toasted but after watching this video im now confident 😊
kevin is low-key funny
By the kw calculations you said kw is always 10^-14. Is it not supposed to be 1×10^-14
You can use both as they are technically the same :)
1×10=10
Sir I'm kinda lost...what did you divide by 2 to get 0,75?
Hi you guys
You might think you understood it
I telling you repeat watching this atleast twice or more it will be more easier than you thought you understood it😭😭
How do i determine which one is limiting by just looking at my calculations
My teacher didn't even touch the Ph calculations 😭😭
Thanks kevin😊
Ye, no cap, I'm finished☹☹
never back down never what
NEVER GIVE UP@@slimza244
@@slimza244never give up!
Explain on how we get the limiting reactant we dont know
how many marks for this type of question ?
Thank you for that😢
will we always have to balance the equation?
If they don't say the equation is balanced then you must always balance
Why was the volume of OH 9, I didn’t quite get that part
Imagine we add the 2 solutions together into a big container. So the volume would be 9.
Then the reaction takes place between the acid and the base.
The acid gets completely destroyed.
But the container volume remains 9.
our definitions of awesome are very different lol
I'm at 10th grade Olympics and learn thoseee
this is so insanely
hard
Can someone explain the limiting reactant part...i dont understand why MgOh ain't a limiting reactant
Go back to grade 11 chemistry!!
Very helpful 😂@@lwandlee.m-f3i