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    0.500g of bronze was reacted with nitric acid giving a Cu2+*solution.* The solution was reacted with iodide ions, I-*forming a solution of iodine, I2.

    This iodine solution*was then titrated with 0.200 mol dm-3*solution of sodium thiosulphate, 22.40cm3*of this was required.

    Calculate the % by mass of copper in bronze


    I did 0.2*(22.40/1000) = 0.00448 which were the moles of thiosulphate which I then divide by 2 to get moles of I2.

    Now that I have moles of I2 - this gives me the moles of Cu2+ which I multiple the mols of I2 by 2 to get. then I do 63.5*mol of Cu2+ to give me mass of copper. Then mass of copper/0.5 * 100 to get percentage composition? Is this method correct?
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    (Original post by MrToodles4)
    Is this method correct?
    Your route through the problem is correct, it is just your molar ratios are a bit squiffy.

    Can you show us your balanced overall reactions between Cu2+ and I- and between I- and S2O32-?
 
 
 
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