You are Here: Home

# Converting delta G units

Announcements Posted on
Would YOU be put off a uni with a high crime rate? First 50 to have their say get a £5 Amazon voucher! 27-10-2016
1. if delta G is 29500 J mol-1
would it be 29.5 kJmol-1 ?

If it was -657824.4 Jmol-1
would it be -658kJmol-1

I'm asking this because my revision guide says the first one is 295 and the second one is -65.8

2. 29 500 = 29.5 thousand (to 3sf)

657 824.4 = 658 thousand (to 3sf)
3. (Original post by kiiten)
if delta G is 29500 J mol-1
would it be 29.5 kJmol-1 ?

If it was -657824.4 Jmol-1
would it be -658kJmol-1

I'm asking this because my revision guide says the first one is 295 and the second one is -65.8

Revision guide is bogus
4. (Original post by AlexFam)
Revision guide is bogus

But its a CGP one
5. (Original post by kiiten)
But its a CGP one
CGP = Crap Guide, People ...
6. (Original post by kiiten)
But its a CGP one
It's also wrong
7. Nah, CGP ones are kinda good but you have to take the information with a bit of salt; try not to rely on it too much.
8. (Original post by kiiten)
But its a CGP one
Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
9. (Original post by alow)
Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
C=O bond energy in CO2 is about 802 kJ mol-1
10. (Original post by alow)
Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
Yeah ques 1.a)i) and 2.a)

- sorry its a bit dark :3
Posted from TSR Mobile
Attached Images

11. (Original post by alow)
Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
I also have another ques - about born haber cycle for KBr.

So if you put KBr (s) at the bottom then on the left hand side (starting from the bottom going up) is it

K (s) + 1/2 Br2 (g)

then

K (g) + 1/2 Br2 (g)

(atomisation of metal)
12. (Original post by kiiten)
I also have another ques - about born haber cycle for KBr.

So if you put KBr (s) at the bottom then on the left hand side (starting from the bottom going up) is it

K (s) + 1/2 Br2 (g)

then

K (g) + 1/2 Br2 (g)

(atomisation of metal)
Bump

Posted from TSR Mobile
13. Any chance you could draw what you're describing in terms of a Born Haber cycle and post a picture? It's quite hard to work out exactly what you mean by your description and a picture speaks 1000 words
14. (Original post by MexicanKeith)
Any chance you could draw what you're describing in terms of a Born Haber cycle and post a picture? It's quite hard to work out exactly what you mean by your description and a picture speaks 1000 words
Oh yeah of course - sorry its a bit messy

Posted from TSR Mobile
Attached Images

15. (Original post by kiiten)
Oh yeah of course - sorry its a bit messy

Posted from TSR Mobile
yes, although with BH it does not matter if you deal with the metal or the non-metal first.

16. (Original post by charco)
yes, although with BH it does not matter if you deal with the metal or the non-metal first.

So was I right to cross out the 1/2 and 2 on Br (see diagram)?
17. (Original post by kiiten)
So was I right to cross out the 1/2 and 2 on Br (see diagram)?
No, you were wrong.

Your first step is atomisation of potassium

Your second step is atomisation of bromine.
18. (Original post by charco)
No, you were wrong.

Your first step is atomisation of potassium

Your second step is atomisation of bromine.
Ah ok, thanks

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: October 4, 2016
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:
Today on TSR

### How to cope with a heavy workload

Poll
Study resources

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.