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

    2
    ReputationRep:
    6.27g of magnesium carbonate were added to an excess of sulphuric acid. The following reaction occurred:
    MgCO3 + H2SO4 ---> MgSO4 +CO2 +H20

    Calculate the mass of MgSO4 produced assuming a 95% yield.

    Moles of MgCO3 = 0.0744

    I got all the calculations correct but why is it 8.958g x 95% / 100

    Doesnt make sense to me, could someone explain it please?
    Offline

    15
    ReputationRep:
    So, once you have calculated the mass of MgSO4 from a perfect 100% yield (8.958), you have to take into account that the percentage yield is not 100, but 95%. Therefore, you can either multiply it by 0.95 (95% expressed as a decimal) or by 95, then divide by 100 (which is the same process, just doing it in two steps).
 
 
 
  • 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 newspaper do you read/prefer?
  • 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.