# Hess law chemistry question (HELP)Watch

#1
Find the enthalpy change for the following reaction using the bond enthalpy data below:

C2H6+3 1/2 O2 -> 2CO2 + 3H2O

C-C= 348
C-H= 412
O=O= 496
C=O= 743
O-H= 463

really lost what to do especially cause the data the question says dosent say enthalpy change of combustion on enthalpy change formation

also why is it mixing in with organic chemistry when they give us a normal equation , someone help plz
0
#2
So i think if i draw the molecular diagram for ethane and the other , would that work ?
0
#3
someone plz
0
1 year ago
#4
Find the enthalpy change for the following reaction using the bond enthalpy data below:

C2H6+3 1/2 O2 -> 2CO2 + 3H2O

C-C= 348
C-H= 412
O=O= 496
C=O= 743
O-H= 463

really lost what to do especially cause the data the question says dosent say enthalpy change of combustion on enthalpy change formation

also why is it mixing in with organic chemistry when they give us a normal equation , someone help plz
It's a question where you need to do
enthalpy change = energy needed to break bonds- energy given out making bonds.
0
#5
(Original post by Gregor99)
It's a question where you need to do
enthalpy change = energy needed to break bonds- energy given out making bonds.
what do i put on the bottom bit of the hess law triangle thing and what do i put on each one , idk what to do
0
1 year ago
#6
It is not Hess's law
0
1 year ago
#7
You work out the energy used for bonds breaking
The energy released from new bonds being made then use the equation I have stated above.
This may have been a method you used at GCSE
0
1 year ago
#8
Find the enthalpy change for the following reaction using the bond enthalpy data below:

C2H6+3 1/2 O2 -> 2CO2 + 3H2O

C-C= 348
C-H= 412
O=O= 496
C=O= 743
O-H= 463

really lost what to do especially cause the data the question says dosent say enthalpy change of combustion on enthalpy change formation

also why is it mixing in with organic chemistry when they give us a normal equation , someone help plz
This is not Hess's law, this is bond enthalpies. Remember break-make (minus the bonds made from the bonds formed).
0
#9
(Original post by Gregor99)
It is not Hess's law
(Original post by Gregor99)
You work out the energy used for bonds breaking
The energy released from new bonds being made then use the equation I have stated above.
This may have been a method you used at GCSE
(Original post by EdexcelAreIdiots)
This is not Hess's law, this is bond enthalpies. Remember break-make (minus the bonds made from the bonds formed).
well i'm thick af , ik what u guys mean now but i got confused cause my teacher literally gave us this sheet with a tittle saying hess's law calculations an question 1 has little to nothing to do with it , thanks guys XD
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• The University of Law
Solicitor Series: Assessing Trainee Skills – LPC, GDL and MA Law - Guildford campus Postgraduate
Wed, 29 Jan '20
• Nottingham Trent University
Wed, 29 Jan '20
• University of Groningen
Fri, 31 Jan '20

### Poll

Join the discussion

#### Why do you want to do a masters?

Great for my career (19)
36.54%
I really love the subject (15)
28.85%
I don't know what else to do (8)
15.38%
I can't get a job (2)
3.85%
My parents want me to (1)
1.92%
I don't know... I just do (7)
13.46%