Professor Organic Chemistry Tutor, thank you for a step by step analysis of the classical Coffee Cup Calorimeter Problem in AP/General Chemistry. Although this material is simple to follow and understand from start to finish, solving word problems is problematic in Science and Engineering.
Dear O-tutor, here is the catch on 7:15 - why is the mass 250g (only water)? Should have been 265g solution = 15g solute + 250g solvent. It is the united system with the specific heat capacity assumed to be 4.184, and the density 1.00, and its temp rises. Am I right?
NES chemistry tests have you add in the 15g of CaCl2 to the q of the rxn in order to get these problems right. Are there 2 ways of doing these problems?...
At 5:08, why is q Rxn = -q H2O? I thought if the temp. of the solution went up, then H2O was absorbing heat, and was therefore (+)? Calorimetry problems severely confuse me for some reason, but your videos have been very helpful so far. Just want to make sure I'm understanding this correctly. Thank you!!!
From the system’s perspective, the CaCl2 is losing heat, so (-), while the water is gaining heat, so (+). It gets very confusing because you have to grapple with the system’s perspective and the surrounding’s perspective. Hope that helps
Some solids will result in exothermic reactions, and some in endothermic (such as NaCl). Exothermic reactions result in -ΔH since the reaction is giving off heat, therefore losing that energy.
Come unto me, all ye that labour and are heavy laden, and I will give you rest. Matthew 11:28 KJV Jesus lives Jesus Christ is Lord For all have sinned, and come short of the glory of God; Romans 3:23 KJV Jesus loves you repent You're a sinner in need of a Savior That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. Romans 10:9-10 KJV
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I am literally watching your videos about 24 hours before my final chemistry exam! Thanks your videos help a lot!
did you pass ?
@@kwanelemakhobotlela7536 Only three of us passed in the entire class...
Imagine enrolling into zoom university for 10k a year and they cannot even properly teach you coffee cup calorimetry :,)
im in normal college for 22k a year
Here in high school taking AP chem, we do one probably and teachers goes, alright I hope you got it!
dude just go to Community college, here in florida panhandle its 3k a year
Professor Organic Chemistry Tutor, thank you for a step by step analysis of the classical Coffee Cup Calorimeter Problem in AP/General Chemistry. Although this material is simple to follow and understand from start to finish, solving word problems is problematic in Science and Engineering.
Your videos help me a lot in my jee preparation in India.Thank you.
Dear O-tutor, here is the catch on 7:15 - why is the mass 250g (only water)? Should have been 265g solution = 15g solute + 250g solvent. It is the united system with the specific heat capacity assumed to be 4.184, and the density 1.00, and its temp rises. Am I right?
this is what i did! because the solution is a mixture of both the CaCl2 and water! My answer was 86.13 kj/mol
@@maggiestorti656 So....do we leave out the 15g of solute or include it with mass? I have a final coming up and would like to get this question right.
C With2Es I’m pretty sure we add it to the 250g!
@@nazuzun5803 OK.
i dont think so because that equation is only for Qh2o, which means to use the mass of h2o by itself
Thanks so much! this was really helpful!
one question, how do you calculate the specific heat capacity of a 1M solution? Is it different than calculating a normal solution?
NES chemistry tests have you add in the 15g of CaCl2 to the q of the rxn in order to get these problems right. Are there 2 ways of doing these problems?...
This guy is single handedly carrying me through high school
At 5:08, why is q Rxn = -q H2O? I thought if the temp. of the solution went up, then H2O was absorbing heat, and was therefore (+)? Calorimetry problems severely confuse me for some reason, but your videos have been very helpful so far. Just want to make sure I'm understanding this correctly. Thank you!!!
is that just a general formula showing that there must be a negative sign in order for them to be equal?
Yes, there must be a negative sign to make them equal. You can put the negative sign on either side of the equation.
From the system’s perspective, the CaCl2 is losing heat, so (-), while the water is gaining heat, so (+). It gets very confusing because you have to grapple with the system’s perspective and the surrounding’s perspective. Hope that helps
@@Pal0maSama so qrxn is for the compound only?
Bless your soul friend
Some of the solution for coffee cup calorimeter, they sum up the mass of water and the reactant. It is true or wrong?
You explain is fabulous thank you so much
in the equation q= mcT ,for m, do we use only the mass of water or the total mass?
i think it should be the total mass so m= mass of H2O + mass of substance
yea he did that wrong. it is supposed to be the total mass, not just the mass of the water
why some times the mass needs to be added with the substance and other times we just use water mass?
Well explained. Thank you
OML, this is amazing, thank you so so so so so ossoosososoos much!
One thing I don't get is that are q solution and q reaction the same? Or q solution and q calorimeter are the same
It is answer for change in internal energy not enthalpy ..
why is qh2o negative? the qrxn is losing heat so shouldn't it be negative and qh2o positive? or does it not matter.
What if we have multiple reagents with a limiting reagent
Is there a derivation for q = mC(delta T)
Does he have any videos on calorimeter constant
idk
thank you.
So are these coffee cup calorimeter problems always going to - ( exothermic )? since the formula has a - on one side
Some solids will result in exothermic reactions, and some in endothermic (such as NaCl). Exothermic reactions result in -ΔH since the reaction is giving off heat, therefore losing that energy.
@@Max-jm6md so endothermic reactions will give positive answers?
if the mass of the water is not given, how can i determine it?
@Jennifer Brown anything about the water is not given, but dont worry i already know it
you are a god
How do you get a 4.184??
It is the specific heat of Water H2O.
Bruhhhh. U shouldve gave the density in the first place. Over all it was a good video.
agree. Makes it so you have to be walked through the question. Not allowing you to get a change to do it first on your own.
The video was very helpful but there where no sigfigs.
surroundins
4:10
i love you
It took u 10 mins to do this and my professor gives us 10 questions in 30 mins ☹️☹️
why dont you ever sigfig?
Drop Your cashapp bro!!!!
Come unto me, all ye that labour and are heavy laden, and I will give you rest.
Matthew 11:28 KJV
Jesus lives
Jesus Christ is Lord
For all have sinned, and come short of the glory of God;
Romans 3:23 KJV
Jesus loves you repent
You're a sinner in need of a Savior
That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
Romans 10:9-10 KJV
how did you know C was = 4.184
Justin Quilnet thats the specific heat of water for me i got it from my textbook but you can also just google it
It will be provided on quizzes typically, unless your teacher told you to memorize some specific ones.
@@orehit3980 can you send me your textbook on conquerjee101@gmail.com thank u
Dude get to the point