GCSE Chemistry - Bond Energies #44 (Higher tier)

This video covers:
- What bond energies are
- That bond breaking is endothermic
- That bond formation is exothermic
- How to calculate bond energies
- Two example calculations

This video is suitable for:
- Higher tier only
- All exam boards
- Triple and combined science

[Cognitoedu]

Hello everyone - please be aware that for the last example, the energy for the reactants actually totals 2249, and not 2330 as we say in the video. Sorry for any confusion that caused!

[thekid]

Just an FYI for anyone watching panicking that they don't get the same answer to the final problem: the answer is actually -97 kJ/mol (still exothermic)

Don't want to complain about the video or videos though. I just wanted to help anyone watching. These videos are very clear and helpful. Many thanks!

[khawlasamir]

Correct Answer for the last example: 2249-2346= -97 KJ/mol exothermic reaction because of the (-) sign.
Thank you Cognito for your clear and straightforward explanation 😊 Keep it up!

[fatemafarahat]

I've been having alot of trouble understanding this topic and calculating overall energy change at school. I just watched this video and I understand everything so well now! Thank you so much! All your videos are awesome and help me aloooot with my studies.

[jackbashford]

I did my own working for the last example, and I didn’t get 2330 for the reactants. I actually got 2249, could you help me?

[zaynabzaman]

thank you, love that these videos can be used at any time
like 2 hours before the exam :D

[giyrglj]

You are so underrated thank you for your work

[imranmughal]

You honestly need more views! The way you teach is wonderful! I told ALL my friends about your channel!!! <3

[erin-iqtm]

im going to fail chemistry omg
edit i got a 9 🤑🤑🤑

[georgefelix]

Love the videos, the best educational YouTube channel out there

[belinadehey]

For the last example i have got -97 as an answer not -16. could you help plox?

[lfmncje]

Hey just wanted to say the question on your website I think is wrong.

Total bond energy of products:
This is what is displayed as the total reaction energy or the energy required to break the bonds of the reactants (on your website).
(3 x 413) + (1 x 339) + (1 x 427) = 2005 kJ
This is what it should be unless I have made a silly mistake.
(1293)+(339)+(427)=2059 kJ
It just means when you subtract your answers the answer is obviously wrong.
Just wanted to say thank you so much for your videos though they have helped me so much along with your website.

[Rimple]

Thanks You So Much, I had Problems With It When I Was Taught In School But You Solved All My Problems.❤

[areebamasood]

i am watching your each and every video with my full attention, i am having my igcse a day after tomorrow and it is really helping me.
Thanks a lot

[thoughtsbright]

I hope you get over 1 million subscribers, you deserve it, I think compund intrest is taking place.
THANK YOU. it really helped me wayyy better than my teacher explaintion.

[rocwsvh]

how are we supposed to know the diagrams of the molecules. like in the last one 2NH3, how are we supposed to know that N binds to 3 H molecules

[unclekabab]

Hey Cognito, Do you ever have to balance an equation first before drawing out the bonds or do they give an already balanced equation in the exam?

[ahmedelamin]

hello i enjoy your videos but i have a question: When hydrogen bonds break, how are you certain that they will react with chlorine instead of hydrogen again?

[maryamalwahaibi]

Omg thank you so much I have a final exam soon and your video helped so much❤.

[Brochesski]

I’m in year 8 and about to have my end of year tests, and this really helped me, Thank you!
Edit: Now i also understand higher level questions and can say that i fully understand this!