Thermochemistry - Free Formula Sheet: bit.ly/3TP4U4u Final Exams and Video Playlists: www.video-tutor.net/ Chemistry 1 Final Exam Review: ua-cam.com/video/5yw1YH7YA7c/v-deo.html
For some reason, there are barely any explanations to this equation on the internet. I've been trying to make sense of this equation was just gonna leave it up to being near the Enthalpy equation and call it a day but the thumbnail of this video called out to me and damn am I thankful for it.
For everybody watching this thermodynamics video is for CHEMISTRY not PHYSICS! So, if you are learning for physics it will not make sense and therefore is wrong.
Once you watch the first video,the one introducing the concept of thermodynamics this observation becomes clearer,but you'd realize that both concepts,physics and chemistry give the same answer,what changes is how you treat work,i.e IN CHEMISTRY:∆u=q+w ;here when work is done on the system it is positive,and that is how the guy on this video has approached the first problem. NOW IN PHYSICS:∆u=q-w ;here when work is done on the system it is negative,so once you insert the value of work with its negative sign the equation becomes; ∆u=q-(- w) which takes you back to the chemistry point of view; ∆u=q+w Therefore both subjects are the same when it comes to the answer but just differ in approaches.
Dude..let me just say that you are the reason I am getting through chemistry. Our professor left halfway through the year, and we were stuck with some bullshit instructors. Thanks for this. Keep it up you're extremely helpful.
your videos help me pass chem. I watch your videos every single week and all I want to say is thanks you a really a life saver. The amount of students your videos help is exponential. I pray that you are getting what you deserve in the form of funds that will allow you to keep doing what you are doing. You are the G.O.A.T
Love u organic chemistry tutor.lots of love and respect from india.i finished my college 2014.in the 4 yrs gap I completely forgot chemistry.bcoz of my family issues .now Ian trying for job . I again start to prepare my subject. Struggled a lot.books not supported.searched chemistry lectures in utube.atlast I found ur videos .u r so helpful to me. No words to express .sincere thanks from my bottom of heart. U r rocking.keep going. I want to see ur face .it's my kind request.....u r helping millions of people. Thank u dear.love u.😍😍😍😍😍😍😍😍😍😘😘😘😘😘😘😘😘😘😘💐💐💐💐💐💐💐😍😘😍😘😍😘
The formula used in finding change in internal energy, the sign was opposite compared to what is being taught on us. The positive and negative of heat and work too.
Professor Organic Chemistry Tutor, thank you for explaining the basics of Thermodynamics and it's powerful impact on AP/General Chemistry. Once again, the practice problems outline the basics of Thermodynamics, which includes Internal Energy, Heat, Work, Pressure and Volume. This is an error free video/lecture on UA-cam TV with the Organic Chemistry Tutor.
. In 3rd sum it is said that . -Surrounding gain 200 means system lost only know (-250) -Now last question surrounding observed mean gain only know that mean system lost only know so,(-500)
Thank you so much sir, My chem teacher rushed with this chapter and I had no idea what waa going on, But you explained everything so clearly, I'm sure I have learned far better. Thank you so much 💗💗
it took me SO LONG to learn that "work being done ON the system" meant that the SURROUNDINGS where doing the work, so w would be positive in the equation since work being done BY the SYSTEM is negative. 💀💀💀💀
I think there's a mistake in the video someone must have noted this but at 18:00 in the video, the work done by the gas in order to expand is supposed to be positive not negative, right? I apply positive work to an object to compress it and the object does positive work to decompress itself, right? To reinforce this logic, at 12:30 we talk about a force being applied on the gas (by the system) to compress it, clearly positive. The work done on the gas to decompress it is negative because the gas is doing the positive work to decompress itself. Can I please get a confirmation? I want to make sure I know my concepts
For the first question, when you apply work to a piston in order to expand it, the volume would increase resulting in a decrease in the pressure due to the force pushing the opposite direction. Hence the equation w=-PV in terms of signs would be, w(-) = (-P) (+V).
@amirabasyouni2552 - I believe you're right. If asking strictly for "work done BY the gas", the answer should be positive because the gas is doing positive work to the surroundings thereby expanding itself. If the gas is expanding and doing positive work to the surroundings, then the work done ON the gas by the surroundings would be negative. When looking at the equations W = -PV and Delta U = Q + W, the W refers to work done ON the gas by the surroundings. A lot of physics problems are based on semantics, which could be tricky at times. Otherwise, great video and tutorial by the OCHEM Tutor; great for learning and reviewing.
Using the gym narrative.. system input would be energy going in (I.e. food) & system out put would be work in the gym? Also, would you class surrounding in terms or climate? Hotter the climate the more energy in? Forgive me if I come across stupid just interested 😂 content is great!
that was also I need to clarify... if in expansion P is negative, then in compression the P must be positive... or maybe W= -p•v is the standard formula🤦🏻
how do you solve the pressure? something like this "Perry wants to design a heat engine with a piston that can produce at least 250 J of energy per pump. How much pressure can his engine make given that the container can only withstand a change in volume of 11.50 L when the gas is ignited."
@@yanggang4352 yeah, that is correct. But the surrounding isn't absorbing heat in this question. The key word is from. That heat energy was absorbed "from" the surrounding not "to" the surrounding. for Ex. Money was given "from" the bank not "to" the bank.
#5 is worded in a very ambiguous way for no reason and that is unfortunately exactly how many professors and chemistry publishers teach it. Its unfortunate and frankly should be banned by the universities because people will get the problem wrong simply because of the confusion with "by" the gas "on" the gas "by the gas system" and "on the gas system", surroundings, ect. The net work being performed by the gas molecules is positive but the net work being performed by the gas system is negative. The question shortens gas system to just gas which is very misleading. In a real world application if you had a gas in a cylinder and your boss says how much work is that gas doing on the cylinder and you say its all good its not doing any work and something explodes you'll be in a lot of trouble and that's what we should be teaching towards in my opinion, real world work applications. Its all word games at the end of the day and that's not what science is about. A fair way to ask this question (#5) would be "A gas system expands from 25L to 40L at 2.5 atm. How much energy is gained by the gas?" You now can understand that the question doesn't pertain to the gas molecules specifically as much as it does the system as a whole. That's just my take. Nothing against the video. Just the way grammar in the U.S and Chemistry meet up to cause chaos. In other countries it's not worded like this so I understand the disagreements pertaining to these formulas. It's also why you get mixed answers from international tutors so be careful getting help internationally.
sadly, this is how the academic system is done. would they change it? doubtful at least tehre is a revolution, but a lot of those people want to keep how their own faculty needs to be different. it has nothing to do with real life. if that was the case many words would be changed in med school, law school but they still keep many old/dead language as part of their education.
I agree, the gas is doing positive work as it loses energy to the system by expansion. I would say the answer is flat out wrong. I guess the equation refers to the work done by the surroundings which in the case of expansion would be negative as the surroundings would gain energy.
That's according to Physics, as it is concerned with surrounding. While in chemistry, the system is taken into consideration and so, the work done by the system is considered negative.
Michelle what you said is absolutely correct. Let me ask you a question. what is minus? what is the physical meaning of minus? Negative is a something set by us human beings, not nature, so its about notations you use. Its not even about Chemistry or Physics. Book on Thermodynamics is written by Cengel and another author Mckonkie. They use opposite signs for work and Heat! Interesting isn't it?
Thermochemistry - Free Formula Sheet: bit.ly/3TP4U4u
Final Exams and Video Playlists: www.video-tutor.net/
Chemistry 1 Final Exam Review: ua-cam.com/video/5yw1YH7YA7c/v-deo.html
Your explanation of why w = -PΔV was incredible. Thanks a ton dude.
For some reason, there are barely any explanations to this equation on the internet. I've been trying to make sense of this equation was just gonna leave it up to being near the Enthalpy equation and call it a day but the thumbnail of this video called out to me and damn am I thankful for it.
I had same doubt bro ......
Right? i was searching everywhere for a thorough yet concise explanation and ochemtutor came to save the day
For everybody watching this thermodynamics video is for CHEMISTRY not PHYSICS! So, if you are learning for physics it will not make sense and therefore is wrong.
not wrong but the opposite.
@@mehmetmehmeti5639 we need some exposure for your comment
How.pls
Once you watch the first video,the one introducing the concept of thermodynamics this observation becomes clearer,but you'd realize that both concepts,physics and chemistry give the same answer,what changes is how you treat work,i.e
IN CHEMISTRY:∆u=q+w ;here when work is done on the system it
is positive,and that is how the guy on this video has approached
the first problem.
NOW IN PHYSICS:∆u=q-w ;here when work is done on the system
it is negative,so once you insert the value of work with its
negative sign the equation becomes;
∆u=q-(- w) which takes you back to the chemistry
point of view;
∆u=q+w
Therefore both subjects are the same when it comes to the
answer but just differ in approaches.
Some works for physics too. Like W=-P∆V then multiplying it with 101.3J to convert L•atm to J
This guy deserves a noble prize fr
He’s the epitome of “Not all heroes wear capes”
Nobel**
@@ObedAdi-wd3yl no i would say he deserves a noble prize as well
Dude..let me just say that you are the reason I am getting through chemistry. Our professor left halfway through the year, and we were stuck with some bullshit instructors. Thanks for this. Keep it up you're extremely helpful.
Literally how's that even legal?
Highly recommended! Very clear explaination with full concepts.
You're literally my professor for all my STEM classes. ILY❣
Your legacy will always be remembered✊️
change you name to "The Tutor" , coz you teach everything so well
my new science and math teacher
your videos help me pass chem. I watch your videos every single week and all I want to say is thanks you a really a life saver. The amount of students your videos help is exponential. I pray that you are getting what you deserve in the form of funds that will allow you to keep doing what you are doing. You are the G.O.A.T
Goat?
Greatest of all time boomer@@mafazchan6817
Love u organic chemistry tutor.lots of love and respect from india.i finished my college 2014.in the 4 yrs gap I completely forgot chemistry.bcoz of my family issues .now Ian trying for job . I again start to prepare my subject. Struggled a lot.books not supported.searched chemistry lectures in utube.atlast I found ur videos .u r so helpful to me. No words to express .sincere thanks from my bottom of heart. U r rocking.keep going. I want to see ur face .it's my kind request.....u r helping millions of people. Thank u dear.love u.😍😍😍😍😍😍😍😍😍😘😘😘😘😘😘😘😘😘😘💐💐💐💐💐💐💐😍😘😍😘😍😘
Once again thank you. I'll leave this comment rn cuz I'll probably use this video on college
Everyone here are students with bad teachers, I haven't gotten to Thermodynamics in school yet and simply watch this for fun. 😂
If I had money I'd pay you, you've helped me a lot
best teacher everrr!!!!
Thank you for your help. I love your videos. They are very comprehensive and yet simple to keep up with. You saved me from a bad grade. :)
Man saved me countless times 🤧🤧❤
you deserve an award more than my profs thank you so much
man, chem is a lot to understand but once you get it, it feels super easy.
I'm using this for thermodynamics
This is so clear thank youuu TwT
The formula used in finding change in internal energy, the sign was opposite compared to what is being taught on us. The positive and negative of heat and work too.
This is for chemistry and not physics. Watch his other video on thermodynamics for physics
watching this the night before my exam, Wish me luck guys
I'll update you guys how it went after classes tomorrow
2 months later.......
8months it’s been…tell us babe!
10months later
Awazing bro keep it up...
Good difference of work done on the system Q+w and work done by the system Q-w
Professor Organic Chemistry Tutor, thank you for explaining the basics of Thermodynamics and it's powerful impact on AP/General Chemistry. Once again, the practice problems outline the basics of Thermodynamics, which includes Internal Energy, Heat, Work, Pressure and Volume. This is an error free video/lecture on UA-cam TV with the Organic Chemistry Tutor.
. In 3rd sum it is said that .
-Surrounding gain 200 means system lost only know (-250)
-Now last question surrounding observed mean gain only know that mean system lost only know so,(-500)
Thank you so much sir,
My chem teacher rushed with this chapter and I had no idea what waa going on,
But you explained everything so clearly, I'm sure I have learned far better.
Thank you so much
💗💗
Thanks for sharing that information ❄️❄️❄️
you deserve the world for these videos
You are crystal clear ❤
You are amazing bro ...
Stay tuned🎗
You are amazing, 5mins in and I understand what my teacher has been trying to teach for the last week.
Very helpful!
23:08: loud silence
Thank you I’ve been struggling with this topic
Thank you very much
I got clarity after your explanation
man ilysm
Thank you so much💖💫
This is powerful keeping on updating
I really enjoyed your lessons
This box is very practical, myself, I use it for explaining autism 😁😁🤘
God bless you my friend
Thank you, it helped me a lot
Thanks Man yu are helping us a lot
love you bro
very useful thank u sir
it took me SO LONG to learn that "work being done ON the system" meant that the SURROUNDINGS where doing the work, so w would be positive in the equation since work being done BY the SYSTEM is negative. 💀💀💀💀
The luckiest day of my life when I entered this channel accidentally.
Damn why couldn't my lecturer just say this in the first place. TYSM
I think there's a mistake in the video
someone must have noted this but at 18:00 in the video, the work done by the gas in order to expand is supposed to be positive not negative, right? I apply positive work to an object to compress it and the object does positive work to decompress itself, right?
To reinforce this logic, at 12:30 we talk about a force being applied on the gas (by the system) to compress it, clearly positive. The work done on the gas to decompress it is negative because the gas is doing the positive work to decompress itself. Can I please get a confirmation? I want to make sure I know my concepts
For the first question, when you apply work to a piston in order to expand it, the volume would increase resulting in a decrease in the pressure due to the force pushing the opposite direction. Hence the equation w=-PV in terms of signs would be, w(-) = (-P) (+V).
@amirabasyouni2552 - I believe you're right. If asking strictly for "work done BY the gas", the answer should be positive because the gas is doing positive work to the surroundings thereby expanding itself. If the gas is expanding and doing positive work to the surroundings, then the work done ON the gas by the surroundings would be negative. When looking at the equations W = -PV and Delta U = Q + W, the W refers to work done ON the gas by the surroundings. A lot of physics problems are based on semantics, which could be tricky at times. Otherwise, great video and tutorial by the OCHEM Tutor; great for learning and reviewing.
Thank you so much !
THANK YOU
I knew that this was going to be difficult but I never thought it'd be like trying to understand Latin
16:07 i love how he remove the little white dot. Because if he did not, I will jokkkk HHAHAHAHAHA
It's lit✨👌
Using the gym narrative.. system input would be energy going in (I.e. food) & system out put would be work in the gym?
Also, would you class surrounding in terms or climate? Hotter the climate the more energy in?
Forgive me if I come across stupid just interested 😂 content is great!
Thanks you
I apologize if you've answered this question, but for question 6, is P negative because work is being done on the system? Thanks :)
that was also I need to clarify... if in expansion P is negative, then in compression the P must be positive... or maybe W= -p•v is the standard formula🤦🏻
we add (-) to make the equation work due to sign conventions
On question 6 if the pressure was applied and the internal energy was kept constant would we still get 12156J if the internal energy is kept constant?
if you love your students OC sir then u better heart this comment
how do you solve the pressure? something like this "Perry wants to design a heat engine with a piston that can produce at least 250 J of energy per pump. How much pressure can his engine make given that the container can only withstand a change in volume of 11.50 L when the gas is ignited."
Please findout workdone by an aneroid barometer in joules per unit volume of cell cylinder of an aneroid barometer ?
Please please please
🥺 thanks
The last question 500J is aborbed so it is endothermic but finally delta U is decreased, so it is endo or exothermic ？
i think work done by the system is positive and work done on the system is negative
no, if WORK done by the system it is negative as it do the work, then if WORK done on the system it will be positive as the system receive the work...
i dont get why P= external pressure when the inner gass does the work (in 16).
why the work isnt equal to the integral of inner gass P(inner gass)ΔV?
Question 6: you said if a gas is compressed the p is positive
maybe it was a mistake, but I think pressure must be positive then the answer will be negative as
W= 8 atm(-15L)
W= - 12,156 J😫
Last one is wrong: is the surroundings absorbe 500J then it should be -500J
The energy was absorbed from the surrounding. That means that the surrounding lost 500J
@@roser8036 Excuse me, if the surroundings absorb heat, doesn't that mean that flows from the system to the surroundings?
@@yanggang4352 yeah, that is correct. But the surrounding isn't absorbing heat in this question. The key word is from. That heat energy was absorbed "from" the surrounding not "to" the surrounding. for Ex. Money was given "from" the bank not "to" the bank.
@@yanggang4352 Not sure if any of that made sense lol. But the system absorb heat energy from the surrounding basically lol
@@roser8036 Yeah, I see your point. I find it a bit ambiguous, but now I get the other meaning. Thanks!
7 question, q value _ 500 ,why u use +500 sir
q was absorbed from the surroundings, in other words q was gained by the system, which gives it a + value
System gains energy
Surroundings lose energy
So, q=+ 500J
9:34
#5 is worded in a very ambiguous way for no reason and that is unfortunately exactly how many professors and chemistry publishers teach it. Its unfortunate and frankly should be banned by the universities because people will get the problem wrong simply because of the confusion with "by" the gas "on" the gas "by the gas system" and "on the gas system", surroundings, ect. The net work being performed by the gas molecules is positive but the net work being performed by the gas system is negative. The question shortens gas system to just gas which is very misleading. In a real world application if you had a gas in a cylinder and your boss says how much work is that gas doing on the cylinder and you say its all good its not doing any work and something explodes you'll be in a lot of trouble and that's what we should be teaching towards in my opinion, real world work applications. Its all word games at the end of the day and that's not what science is about. A fair way to ask this question (#5) would be "A gas system expands from 25L to 40L at 2.5 atm. How much energy is gained by the gas?" You now can understand that the question doesn't pertain to the gas molecules specifically as much as it does the system as a whole. That's just my take. Nothing against the video. Just the way grammar in the U.S and Chemistry meet up to cause chaos. In other countries it's not worded like this so I understand the disagreements pertaining to these formulas. It's also why you get mixed answers from international tutors so be careful getting help internationally.
sadly, this is how the academic system is done. would they change it? doubtful at least tehre is a revolution, but a lot of those people want to keep how their own faculty needs to be different. it has nothing to do with real life. if that was the case many words would be changed in med school, law school but they still keep many old/dead language as part of their education.
I agree, the gas is doing positive work as it loses energy to the system by expansion. I would say the answer is flat out wrong. I guess the equation refers to the work done by the surroundings which in the case of expansion would be negative as the surroundings would gain energy.
@@Gojojojojojo his answer is negative -3799J which is correct, he just almost forgot it.
Actually, work done by the system is positive, while work done on the system is negative!
That's according to Physics, as it is concerned with surrounding. While in chemistry, the system is taken into consideration and so, the work done by the system is considered negative.
thought asians were supposed to be smart? Mark wahlberg gets it.
Michelle what you said is absolutely correct. Let me ask you a question. what is minus? what is the physical meaning of minus? Negative is a something set by us human beings, not nature, so its about notations you use. Its not even about Chemistry or Physics. Book on Thermodynamics is written by Cengel and another author Mckonkie. They use opposite signs for work and Heat! Interesting isn't it?
You decreased lots of entropy on so many people lol
i love you
Is this not more a thermaldynamics question
Am sorry sir I disappointed you on my test I got 11/14😢.
got 12/15
i hate physics cz always teacher talks about w and q without explaining what are those letters
These sign conventions are not for physics ... they're for chemistry
me studying:
no one: random game ad pops up
:))
I NEED MOOOOOOOORRREEE
The first problem you did was wrong as work is negative if it is done by the system!
That question literally states that work is done on the system
wiiiiild
cringe
i love you