The EASIEST Method For Solving Hess Cycles

In this video, I show you my method for solving Hess cycles, which will hopefully be easier than the way you learnt at school.
Timestamps:
0:00 - Introduction
0:16 - What is an enthalpy change?
1:26 - What is Hess's Law?
1:54 - What is a Hess cycle?
2:27 - Solving a Hess cycle using formation enthalpies
7:23 - Solving a Hess cycle using combustion enthalpies
9:57 - Solving a Hess cycle using bond enthalpies
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#chemistry #alevel #physicalchemistry #education

[@josimjosim1000]

i cant believe how easy hess cycles are thanks to your explanation

[@LieChess]

Well said, well said (applause). You have single handedly saved the education system and future aspirations of 40,000 people. Good Job!

[@MMK-PALESTINA]

This is an Underrated channel, Thanks for saving my time and saving my grades in the exam, I hope the best for you and your channel, Keep going.

[@KBMFilms2020]

Wow, real eye opener, my teacher kept telling me other things i found confusing. Thank you very much sir.

[@aakyjj]

after 2 years i finally understood it thank u sm

[@hi-ow3hb]

Absolutely amazing, thanks!

[@compequiet0584]

Thanks man, you're a grade saver!

[@sadiaiditry]

I had problem deciding the direction of the arrow and how to make a equation. Now I finally get it, thanks 😊.

[@Alienokojigaming]

TYSM, for this wonderful explanation.

[@fspar]

Amazing video, you deserve a lot more!

[@joe_ninety_one5076]

Excellent step by step tutorial

[@mysticgoat8699]

Thank you maj you really made me understand hess law now it doesnt confuse me anymore may God bless you

[@itsmeminhaz3784]

most underrated channel

[@smoothcriminal5650]

Thanks a lot sir, this is a very helpful video 😊

[@AYNatheacaiAYNAtheacai]

Thank u so much can't imagine how much u saved me ❤❤❤

[@liza.56]

Besttt explanation ever 🤩

[@goddidezzz]

best vid on youtube explaining this topic

[@kgh22]

You have explained it so beautifully. Thank you for your work! Gudjob🩷

[@va_rs_ha_]

Thank you ❤

[@soogist]

youre a lifesaver

[@javedfaizal5473]

You deserve a million subscribers!! thank you for this!!

[@Chemistorian]

Thanks, I'm glad you enjoyed it :)

[@vortax521]

@@Chemistorian thank you man😁😁

[@maarinahope]

Wow !! This is extra ordinary. Please try to make more videos on redox as well

[@maykyisunaing5597]

Thanks a million. I'm so confused about bond enthalpy cycle. Now it's clear for me.Can you upload other more examples for bond enthalpy cycles?

[@abdulemalik8848]

Thank you.

[@vinuthjayasuriya6466]

Thank you. You saved me big time….

[@azanahmad8561]

Bro Saved me!!!!!!

[@loxionNam]

You the best man 😇😇😇😇😇

[@agosmastro7399]

If we do it this way in the A-Levels, do we still get the full mark?

[@Chemistorian]

Absolutely! As long as you come out to the correct answer, you'll get the marks.

[@uncloned69]

good explanation

[@Islamicreminder19]

Thanks a lot this was really helpful....

[@Islamicreminder19]

This was much more understandable than anything else I've been taught

[@MemerGirlFatima]

Easiest explanationn🖤🖤🖤 love from pakistan

[@nikarta1]

Please can you also do how you do the rearranging?🙏

[@mihindi67]

omg i dont know who you are omg i love u so much you made my day thank you so much

[@cultured8709]

tysm man

[@humamumtaz2218]

u are amazinggg :)) understood

[@--katkat]

Thank you thank you 😊

[@Prismo786]

Could you upload more examples? i understood but wld be more confident with more practice

[@abdulemalik8848]

Thank u

[@jrxzz1398]

thankyou bro

[@Ojisgay]

I mean if you think about it all the routes have to add up to 0 so you could also just add up the other 2 and work out the final one from that

[@pratyasha279]

if some of the formation enthalpies of the compounds are not given for a combustion reaction, how do we go from there?

[@insulin8031]

Bruda fr I love ya

[@saradeaf-mh6gu]

hi do we have t use the arrow method? can i just use products-reactants

[@bella-iu7bl]

would u consider making videos on rates of reaction / equilibriums bc i’ve always found it hard to tell what side the reaction would shift too if temp changes etc

[@Chemistorian]

Funnily enough, my next video (coming out in a couple of days) is going to be on equilibrium constants, but I can definitely make a longer video on rates & equilibria if it'll be helpful.

[@bella-iu7bl]

@@Chemistorian that’d be perfect thank u!

[@syedmohammadaun-ne5du]

Legend

[@kari2136]

Thank you very much for your video tutorial. I have a couple of questions, why do you use H(c) when explaining the formation of the hess cycle, and during the combustion you use H(f). is it correct? we were taught that enthalpy change formation is H(f), and combustion is H(c)

[@Chemistorian]

During the enthalpy of formation example, we have been given enthalpies of formation, and we use them to construct a FORMATION Hess cycle, in order to work out the enthalpy of combustion of methane. That reaction at the top could have been anything, but in this case, it shows the enthalpy of combustion of methane. We still construct a FORMATION Hess cycle here, because we've been given values of Hf, NOT Hc. For the second example, it's just the other way around. We've been given Hc values, so we construct a COMBUSTION Hess cycle to work out the enthalpy change for the reaction at the top, which happens to be the formation of benzene. So in the first example, we're using enthalpies of formation to work out the enthalpy of combustion of methane, and in the second example, we're using enthalpies of combustion to work out the enthalpy of formation of benzene.

[@emanilyas4749]

amazinggg

[@riazhoque8829]

Hi, just wanted to ask for the Hess cycle we can still use the top arrow as the biggest route can’t we when trying to figure out the enthalpy of combustion

[@Chemistorian]

There is no “biggest route”. Hess’s law states that as long as you start at the same place and end at the same place, any route you take will have the exact same enthalpy change. So, you can take any route you want!

[@caraevans2114]

Hi, I’m confused on the bond enthalpy section. Why do the arrows face downwards? Is it due to the reaction being combustion?

[@xdbackflip]

They actually point upwards but this guy's not smart so he's doing it a dumb way where the elements in their standard states are on the left. Because this guy is dense he failed to mention this.

[@vortax521]

TYSM MAN, This literally saved my LIFE IN AS level, tysm😁😁😁😁

[@Chemistorian]

Glad I could help!

[@juddbanas7208]

In example 1, why were we able to use the delta hf of H2O even if the given is for gas and the reaction indicates that H2O is in liquid state

[@Chemistorian]

That's because there's a mistake in the video that I hadn't noticed before. The Hf for water in the table is actually given for the liquid state, not the gas state. Thanks for pointing that out!

[@chanisperera103]

can u pls do a detailed video on Esters

[@Chemistorian]

I'll add it to the list, but I actually have a section on esterification in my first video - kzbin.info/www/bejne/mmG9mHduosaSgdE.

[@chanisperera103]

@@Chemistorian ok thank you

[@kxtiger9892]

Isn't rearranging just reversing the symbols, though i don't get the purpose of the extra step

[@Obaid-Ur-Rahman342]

4:57 If they are asking for 1 mole shouldn't we half the the moles of H20. Can anyone please explain

[@Chemistorian]

The combustion of 1 mole of CH4 results in the formation of 2 moles of H2O.

[@myaestheticlife7403]

wow

[@elizabeth-ty3he]

I still can't wrap my brain around the difference btwn q and H. Help! Is it that heat is transfer of energy btwn moleculesand H iis overall gain or loss of heat energy?

[@Chemistorian]

When in doubt, check the units! Q is measured in J or kJ, so it’s just the amount of heat energy taken in/given out during a reaction. H is measured in kJ/mol, so it’s the amount of heat energy taken in/given out during a reaction, PER MOLE of reactant.

[@elizabeth-ty3he]

@@Chemistorian thnx!

[@user-vn1fg2zj2g]

Why is water in the table for enthalpies of formation in a gaseous state if it’s meant to be in its standard state?

[@Chemistorian]

Well spotted! There's a mistake in the video. Another commented pointed this out too. The Hf for water in the table is actually given for the liquid state, not the gas state.

[@user-vn1fg2zj2g]

@@Chemistorian Thanks for the reply, much appreciated.

[@zaino9818]

I still don't understand how you determine the direction the hess cycles arrows go

[@Chemistorian]

It all depends on the type of Hess cycle. If it uses formation enthalpies, arrows go up from the box because the formation enthalpy is always going from the elements to the compounds. If it uses combustion enthalpies, arrows go down to the box because the combustion enthalpy is always going from the compounds to the combustion products. When you learn the definitions of the enthalpy changes, the directions of the arrows make sense logically.

[@zaino9818]

@@Chemistorian ah okay. thanks for your help

[@xdbackflip]

Poor combustion explanation.

[@darrenj.griffiths9507]

ummm, no!.. Next