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

    1
    ReputationRep:
    prediced grade boundries... opinions please
    Offline

    1
    ReputationRep:
    I forgot to multiply the hydration enthalpy of the chloride ion by 2 so ended up with an endothermic deltaH solution which is wrong. How many marks do you reckon I'd get for the solubility question having made the error in the previous q? Would I get many follow through marks?
    Offline

    1
    ReputationRep:
    was the enthalpy of solution 775 (something like that) ??
    Offline

    1
    ReputationRep:
    (Original post by vinchy)
    delta G got -65.1
    thing is though, the given values for the question if you didnt get an answer was -250. not dividing by two gave you a closer answer, thats why im thinking you dont have to divide
    Offline

    16
    ReputationRep:
    (Original post by Suits101)
    The question asked you to calculate the STANDARD enthalpy and entropy change, which was asked on Jan 13 I believe and you had to divide by two.
    If you're right, I love you.
    Offline

    13
    ReputationRep:
    (Original post by Azzer11)
    If you're right, I love you.
    Divide what by 2??
    Offline

    2
    (Original post by JC25)
    I forgot to multiply the hydration enthalpy of the chloride ion by 2 so ended up with an endothermic deltaH solution which is wrong. How many marks do you reckon I'd get for the solubility question having made the error in the previous q? Would I get many follow through marks?
    As long as explanation was right, you should be fine.
    Offline

    8
    ReputationRep:
    (Original post by Osalim1998)
    thing is though, the given values for the question if you didnt get an answer was -250. not dividing by two gave you a closer answer, thats why im thinking you dont have to divide
    No it wasn't. -250 was given value for delta H.
    Offline

    1
    ReputationRep:
    It was an okay paper, I made quite a few silly mistakes. With method marks and ecf, hopefully I haven't lost more than 30 if I got 70 on both paper, and a C and hopefully a B/A from my resit from last year. Aswell as an A on course work and a C on course work this year. Could I scrape an A overall??
    Offline

    2
    ReputationRep:
    (Original post by vinchy)
    I got that because for standard enthalpy i used SO2+1/2O2.> SO3
    GOT -98.5KJMOL-1
    It wanted enthalpy change of the reaction not standard enthalpy of formation?
    Offline

    2
    (Original post by Cadherin)
    Divide what by 2??
    Did you said SA has an effect on emf?
    Offline

    2
    (Original post by Kay Fearn)
    It wanted enthalpy change of the reaction not standard enthalpy of formation?
    Enthalpy change can be calculated from standard enthalpy of formation, which is what you were given and used.
    Offline

    1
    ReputationRep:
    (Original post by RefusedAccess)
    Question stated that solubility is defined as the amount of solid able to dissolve in water, so as it is an endothermic reaction, more MgCl2 is produced if you increase temperature, hence solubility is increased
    Why is it endothermic if DHsolution for the forward reaction was a negative value?
    Offline

    1
    ReputationRep:
    (Original post by koolgurl14)
    Should I do an unofficial or is there already done unofficial ms or anyone started doing one
    please do one
    Offline

    16
    ReputationRep:
    (Original post by Cadherin)
    Divide what by 2??
    The equation they gave you for the Contact Process involved the formation of 2 moles of SO3. So I halved the moles to get SO2 +1/2O2 ----> SO3 and used this equation to work out enthalpy/entropy. Not 100% confident it was the right thing to do.
    Offline

    8
    ReputationRep:
    (Original post by Kay Fearn)
    It wanted enthalpy change of the reaction not standard enthalpy of formation?
    Thats what I remember they asked for, I'm getting so stressed atm 😂😂


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by Suits101)
    Enthalpy change can be calculated from standard enthalpy of formation, which is what you were given and used.

    Yes but people are saying you have to divide the so3 and so2 values by 2

    it asked for the enthalpy change of the reaction so i don't think you had to divide by 2?
    Offline

    3
    ReputationRep:
    (Original post by Osalim1998)
    thing is though, the given values for the question if you didnt get an answer was -250. not dividing by two gave you a closer answer, thats why im thinking you dont have to divide
    those two values are normally irelevant.I just could not get over STANDARD
    Offline

    2
    ReputationRep:
    (Original post by Kay Fearn)
    It wanted enthalpy change of the reaction not standard enthalpy of formation?
    I genuinely don't recall them asking for standard either, dunno if Azzer is right or not.

    confirm anyone who remembers what the deltaH question asked for?
    Offline

    1
    ReputationRep:
    (Original post by tbh12)
    No it wasn't. -250 was given value for delta H.
    and for delta s aswell
 
 
 
Poll
Do you agree with the PM's proposal to cut tuition fees for some courses?

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.