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

Im doing a past paper and im confused on a few of the answers? Watch

Announcements
    • Thread Starter
    Offline

    5
    ReputationRep:
    1.12g of iron reacts with oxygen to form 1.60g of an oxide of iron. what is the formula of this oxide of iron? I know the answer is Fe2O3.
    1.12/ 56 = 0.02
    1.60 / 16 = 10

    how does this become a ratio?

    2) in an experiment 1.226g of Kclo3 was heated. A mass of 0.32g of oxygen gas was collected. What is the oxygen percentage yield fort he experiment??

    0.320g / (0.320/16) = 0.02 --> 0.320/0.02 = 6.4 *100

    I know its wrong but im confused :/
    Offline

    1
    ReputationRep:
    (Original post by Hazel99)
    1.12g of iron reacts with oxygen to form 1.60g of an oxide of iron. what is the formula of this oxide of iron? I know the answer is Fe2O3.
    1.12/ 56 = 0.02
    1.60 / 16 = 10
    how does this become a ratio?
    You need to use the mass of oxygen that has reacted
    1.60g is not the mass of oxygen
    mass of oxygen=1.60-1.12=0.48g
    0.48/16 = 0.03
    1.12/56 = 0.02
    Therefore Fe : O is 2 : 3
 
 
 
  • 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
    Should Spain allow Catalonia to declare independence?
  • 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.