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

    16
    ReputationRep:
    If i add 2g of KHCO3 to 30cm^3 of 1gcm^-3 solution.

    when i work out the enthalpy change from mass of solution x 4.18 x Temperature change.

    Is the mass of solution 32 or 30 g. If it was mass of mixture is would be 32 but i dont know if KHCO3 dissolves and therefore should be counted as part of the solution.

    Thanks alot
    Offline

    11
    ReputationRep:
    (Original post by Goods)
    If i add 2g of KHCO3 to 30cm^3 of 1gcm^-3 solution.

    when i work out the enthalpy change from mass of solution x 4.18 x Temperature change.

    Is the mass of solution 32 or 30 g. If it was mass of mixture is would be 32 but i dont know if KHCO3 dissolves and therefore should be counted as part of the solution.

    Thanks alot
    can you add 2 g and 30 cm cube together? (think of whether you can 1 apple and 1 orange together)
    • Thread Starter
    Offline

    16
    ReputationRep:
    (Original post by shengoc)
    can you add 2 g and 30 cm cube together? (think of whether you can 1 apple and 1 orange together)
    I gave the mass per unit volume if you read my question.
    Offline

    2
    ReputationRep:
    1g = 1cm^3 so you can actually add them two values together. You'd use 30 though. You'd only use the 2g when you're figuring out how many moles of KHCO3 reacted
    Offline

    11
    ReputationRep:
    (Original post by Goods)
    I gave the mass per unit volume if you read my question.
    true, but what i was trying to imply was that you can't make sense of adding the two up with their current units unless you convert one of them based on the density information.

    i.e. apple is a fruit, orange is a fruit. i have two kinds of fruits there. i have just "added" them up based on a common feature.
 
 
 
  • 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
    What's your favourite Christmas sweets?
  • 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.