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

    0
    ReputationRep:
    Hey! I'm really struggling with unit 3 of the higher chemistry course and was wondering if anybody could help me out with a few questions?

    1.What is the relationship between
    enthalpies p, q, r and s?
    S(s) + H2(g) H2S(g) H=p
    H2(g) + ½ O2(g) H2O(l) H=q
    S(s) + O2(g) SO2(g) H=r
    H2S(g) + 1½ O2(g) H2O(l) + SO2(g) H=s
    A. p = q + r – s
    B. p = s – q – r
    C. p = q – r – s
    D. p = s + r – q

    2.The ion-electron equations for a redox
    reaction are
    2I-(aq)→I2(aq) + 2e-
    MnO4-(aq) + 8H+(aq) + 5e→Mn2+(aq) + 4H2O(l)
    How many moles of iodide ions are
    oxidised by one mole of permanganate
    ions?
    A. 0.2
    B. 0.4
    C. 2
    D. 5
    • Community Assistant
    • Study Helper
    Offline

    15
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by ralph123456)
    Hey! I'm really struggling with unit 3 of the higher chemistry course and was wondering if anybody could help me out with a few questions?

    1.What is the relationship between
    enthalpies p, q, r and s?
    S(s) + H2(g) H2S(g) H=p
    H2(g) + ½ O2(g) H2O(l) H=q
    S(s) + O2(g) SO2(g) H=r
    H2S(g) + 1½ O2(g) H2O(l) + SO2(g) H=s
    A. p = q + r – s
    B. p = s – q – r
    C. p = q – r – s
    D. p = s + r – q
    Construct the final equation by judicious addition and subtraction of the others, always using the four rules of number ...
    2.The ion-electron equations for a redox
    reaction are
    2I-(aq)→I2(aq) + 2e-
    MnO4-(aq) + 8H+(aq) + 5e→Mn2+(aq) + 4H2O(l)
    How many moles of iodide ions are
    oxidised by one mole of permanganate
    ions?
    A. 0.2
    B. 0.4
    C. 2
    D. 5
    permanganate requires 5 moles of electrons, while iodide only provides 2 moles ...

    This is maths ..
    Offline

    0
    ReputationRep:
    I'm doing higher chemistry and I'm really struggling with unit 3 too! I have my NAB on monday and second prelim the next day! This isn't going to go well.
 
 
 
Poll
Who is your favourite TV detective?

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

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