You are Here: Home

# bond enthalpies watch

1. Help on question 2 pls

EricPiphany samb1234
Attached Files
2. 2.1 Exercise 2 - Bond dissocation enthalpies.doc (33.5 KB, 54 views)
3. (Original post by thefatone)
Help on question 2 pls

EricPiphany samb1234

You know , and
4. (Original post by Kvothe the arcane)
multiple don't make a difference right? so i put a 3 in from of the H2 and a 2 in from of the ammonia

so what did you work out the average bond enthalpy as?
5. (Original post by thefatone)
Help on question 2 pls

EricPiphany samb1234
Spoiler
6. (Original post by EricPiphany)
Spoiler
sure? the answers tell me +390.8 kJmol-1 but i get the same answer as you.....
7. (Original post by thefatone)
sure? the answers tell me +390.8 kJmol-1 but i get the same answer as you.....
I get

Your mistake is that enthalpy change of formation is when one mole of the product is formed.
8. (Original post by Kvothe the arcane)
I get 390.83

Your mistake is that enthalpy change of formation is when one mole of the product is formed.
You're correct.
9. (Original post by thefatone)
multiple don't make a difference right? so i put a 3 in from of the H2 and a 2 in from of the ammonia

so what did you work out the average bond enthalpy as?
No. But then you would have to multiply by 2 as 2 moles of NH3 are being formed. Your answer isn't that far off as you're dealing with large quantities and 46 is small in comparison.
10. (Original post by Kvothe the arcane)
No. But then you would have to multiply by 2 as 2 moles of NH3 are being formed. Your answer isn't that far off as you're dealing with large quantities and 46 is small in comparison.

ah right i forgot thanks a ton guys

(Original post by EricPiphany)
You're correct.
11. I guess I'm too late

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 14, 2016
Today on TSR

### He lied about his age

Thought he was 19... really he's 14

### University open days

Wed, 25 Jul '18
2. University of Buckingham
Wed, 25 Jul '18
3. Bournemouth University