Thank you so much for the video! You made Hess cycle seem less scary and actually much easier to understand than from the textbook😁
@newplatypus5 жыл бұрын
This is the one topic I never understood but this is so well explained and simple, I now finally get it. Thank you so much!
@aaryanramani1699 Жыл бұрын
My favourite videos for ENTHALPY.... Thanks so much for explaining the definitions and conditions so clearly!!!
@AlleryChemistry Жыл бұрын
No problem!
@livyaxx82036 жыл бұрын
Hello, I was hoping if you could make a video on hardest calculation questions in chemistry. Thanks!
@arjunaich53992 жыл бұрын
Is it just me or are the cycles the wrong way round for the questions. For calculating the enthalpy of formation, he drew a combustion cycle and vice versa for enthalpy of combustion.
@simranxpanesar78532 жыл бұрын
This was really well explained however I'm slightly confused about how you work out what goes at the bottom of the cycle and the number of moles it has, could you explain it for me please?
@aks64405 жыл бұрын
how did you balance the numbers at the bottom of the enthalpy cycle I don't get that bit
@zaynaba66266 жыл бұрын
Thank you! your videos are live savers!
@joeknox21875 жыл бұрын
Hi Chris, in combustion cycles do you never count the enthalpy of combustion of oxygen?
@Tibialisanterior6 жыл бұрын
at 22:36 did you mean this the 'enthalpy of formation'?? isnt it meant to be combustion due to our arrows facing down?
@AneeqAli-o6q5 күн бұрын
No, look at the data, if the data is about enthal0y of combustion then the arrows face down. Doesn’t matter what they ask for. The arrows are related to the data
@acegamer25566 жыл бұрын
19:05 Why is there only 1 carbon in elements for formation isnt there supposed to be 2 Carbons as there is one in methanol and one in carbon dioxide?
@p.p63434 жыл бұрын
For calorimetry the question gives the temperature change in degrees Celsius, so do we not convert to this to kelvin? In the markscheme it's not converted to kelvin. Thank you
@AlleryChemistry4 жыл бұрын
Hi. Yes you need to know the change in temperature. The change in temperature is the same whether it is in kelvin or degrees Celsius. However all temperature must be quoted as kelvin.
@farhaanahmed89243 жыл бұрын
What an amazing man.
@trihardFTW7 жыл бұрын
Hi there, what do you mean by "start anywhere on the cycle and add up the numbers" - i don't understand what numbers you're talking about? if you can clarify this. thanks!
@AlleryChemistry7 жыл бұрын
Yes. You have the enthalpy values next to the arrows. Start anywhere on the cycle and add the numbers up until you get back to where you started from. Change the sign if you go against an arrow, keep the sign the same if you are going with an arrow. It should add up to 0.
@trihardFTW7 жыл бұрын
Ohhh. i get it now! so for the first example, if you start from -234 and go up, then add -732 and go across, and then add +966 as you're going against the arrow, it = 0. this clears it up, thanks!
@AlleryChemistry7 жыл бұрын
That's it! Pretty smart isn't it! Just a way of making sure your numbers are definitely correct.
@ellasidney22 жыл бұрын
at 18:05, why did you use 1.5O2 rather than 3O2?
@Rah66 Жыл бұрын
ik im like 8 months late but its cus he was balancing the equation
@shyamkanjee64096 жыл бұрын
So basically bond dissociation enthalpy is the energy required per mole to break the intermolecular forces of attractions between the gaseous compounds, like Cl2?
@mtsl77803 жыл бұрын
no, the reaction given shows formation. but your given the units for enthalpy of combustion. meaning you have to follow the combustion route
@sabthesarcastic3 жыл бұрын
Hello sir just wondering for 9:36 where did 1662 come from I don't get it
@abi.anderson4 жыл бұрын
Hi, what if you are given the values for enthalpy of reaction and need to find the enthalpy of combustion or formation? Which way do the arrows go?
@AlleryChemistry4 жыл бұрын
You purely go off the data they have given you. If they have given you combustion data then you draw a combustion cycle, if they have given you formation data then you draw a formation cycle. Either will allow you to work out enthalpy of reaction.
@abi.anderson4 жыл бұрын
@@AlleryChemistry Thank you!
@joeatty44416 жыл бұрын
For the calorimetry equation does temperature have to be in K?
@anotheryoutubeuser12984 жыл бұрын
it doesnt matter whether its in C or K...late reply huh XD
@shyamkanjee64095 жыл бұрын
Hey Chris, are these videos for the old spec or the new one?
@julkamikula15536 ай бұрын
amazing thanks so much saving my mocks !!!
@AlleryChemistry6 ай бұрын
You're welcome 😊
@h.95093 жыл бұрын
for q2 why is the temp not in kelvins?
@joeknox21875 жыл бұрын
or is the oxygen just used to balance the equations?
@yassiec52944 жыл бұрын
this is SO. HELPFUL. thank you
@AlleryChemistry4 жыл бұрын
Glad it was helpful!
@Ilya_0129 ай бұрын
You are the best❤
@njfrnjn3 жыл бұрын
16:20
@slapmynutz2 жыл бұрын
ur a fucking legend mate
@otty8530 Жыл бұрын
habibi this video v good one
@soyadrink9831 Жыл бұрын
I get 50 for the Mr of ethanol
@reubenconstantine26855 жыл бұрын
Sir I have a massive issue I need help trying to understand... if products have higher energy than reactants surely that means it’s exothermic as more energy is released when the product is formed than the energy required to break the reactants’ bonds? Yet the diagram is labelled endothermic?
@nakshatrasatheesh81384 жыл бұрын
if the products have higher energy it means they've absorbed energy. that's why the diagram is labelled as endothermic
@samkoffi81736 жыл бұрын
Don't we have 4 lots of C=O as each CO2 has 2 C=O bonds?
@tanveersandhu47963 жыл бұрын
did you find the answer to this?
@MARIBOO6716 жыл бұрын
This was super helpful thankyouuuu
@samiramustafa23544 жыл бұрын
is this for AS level too?
@tawanamufasa2914 жыл бұрын
yes its in module 3 and as level is from modules 1 -4
@sea52055 жыл бұрын
Yr videos are amazing
@huda38645 жыл бұрын
In the q=mc^T, temp is in K so aren’t you meant to convert into from °C to K but in the example you didn’t I’m confused
@anotheryoutubeuser12984 жыл бұрын
are you still confused?
@HamzaKhan07113 жыл бұрын
@@anotheryoutubeuser1298 I am. Why isn't there a conversion to K from degrees celsius? When do you convert to K in the q equation?
@toffeefawn51773 жыл бұрын
@@HamzaKhan0711 it doesn’t matter for those type of questions
@anakinskywalker37773 жыл бұрын
@@HamzaKhan0711 you do convert he just forgot
@idontknow1630 Жыл бұрын
@@HamzaKhan0711 because the delta T means 'change in temperature' even if you convert to kelvin the actual temp change is still gonna be the same eg 20 C to 26 C --> changes by 6 293 K to 299 K --> changes by 6