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

    0
    ReputationRep:
    Calculate how much Zn(NO3)2 · 6H2O (in grams) is needed to prepare 0.5L of 1000 mg Zn/ L solution knowing the following data: Molar mass of Zn is 65.38 g/molMolar mass of Zn(NO3)2 · 6H2O is 297.49 g /mol.Your answer must be given with 3 digits, for example X.YZ g

    Please help! very confusing question!
    Offline

    3
    ReputationRep:
    (Original post by steffff)
    Calculate how much Zn(NO3)2 · 6H2O (in grams) is needed to prepare 0.5L of 1000 mg Zn/ L solution knowing the following data: Molar mass of Zn is 65.38 g/molMolar mass of Zn(NO3)2 · 6H2O is 297.49 g /mol.Your answer must be given with 3 digits, for example X.YZ g

    Please help! very confusing question!
    Work out:

    1) Mass of zinc you need for 0.5L
    2) Number of moles of zinc that equates to. this will be the number of moles of hydrated compound needed.
    3) Mass of hydrated salt needed.

    All done with moles = mass / Mr (or Ar)
    • Thread Starter
    Offline

    0
    ReputationRep:
    thank you for your reply.
    I understand how to obtain the mass at the end from the formula, however I dont understand how to get the moles from the 0.5L of 1000mg Zn/L?
    Offline

    3
    ReputationRep:
    (Original post by steffff)
    thank you for your reply.
    I understand how to obtain the mass at the end from the formula, however I dont understand how to get the moles from the 0.5L of 1000mg Zn/L?
    If 1L contains 1000mg (1g) how much does 0.5L contain?
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 25, 2015
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.