Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    10
    ReputationRep:
    Hi all ,
    This is a really stupid question but it's a trap I always fall into .I need to be sure.

    Let's say I have the following reaction ;

    2A + 3B -->> C + D and the mass of A is 10g.To work out number of moles I know I'll use n=m/Mr
    For the Mr I don't multiply the co-efficient and all the individual masses of the elements in A right?


    Posted from TSR Mobile
    Offline

    17
    ReputationRep:
    If you have 10 g of A, it doesn't matter what you react it with, the number of particles will be the same, hence the number of moles of A you have is unaffected.

    So, you're correct.
    Offline

    10
    ReputationRep:
    Nope, if A is an element, just the mass number and if a compound, add the mass numbers together. No multiplying to be done.
    2 moles would be the theoretical amount, you're calculating the actual number of moles.
 
 
 
Poll
Do you like carrot cake?

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.