Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    17
    ReputationRep:
    Hi,

    I am slightly confused with this and was wondering if anyone could help.

    So there are no numbers I need to input yet, I am just trying to understand the process:

    2C + 3H2 = C2H6 (formation)

    ∆H1 = 2CO2 and ∆H2 = H2o

    What I don't get is why are we only using Carbon on one side and Hydrogen on the other?

    The other problem I really don't get...

    2C + 3H2 + 1/2 O2 = C2H5OH

    ∆H1 = 2CO2 and ∆H2 = 3H2O

    Why 3 moles of hydrogen? There isn't 3 moles of hydrogen in the products?

    Sorry for sounding thick? Any help is greatly appreciated
    • Community Assistant
    • Study Helper
    Offline

    14
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by Lambert87)
    Hi,

    I am slightly confused with this and was wondering if anyone could help.

    So there are no numbers I need to input yet, I am just trying to understand the process:

    2C + 3H2 = C2H6 (formation)

    ∆H1 = 2CO2 and ∆H2 = H2o

    What I don't get is why are we only using Carbon on one side and Hydrogen on the other?

    The other problem I really don't get...

    2C + 3H2 + 1/2 O2 = C2H5OH

    ∆H1 = 2CO2 and ∆H2 = 3H2O

    Why 3 moles of hydrogen? There isn't 3 moles of hydrogen in the products?

    Sorry for sounding thick? Any help is greatly appreciated
    It looks like you are using formation enthalpy to work out other enthalpy changes, but it's not very clear.

    Check out this interactive on Hess' law for a full explanation.
 
 
 
  • See more of what you like on The Student Room

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

  • Poll
    Have you ever participated in a Secret Santa?
  • See more of what you like on The Student Room

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

  • 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

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