Chemistry · Oct / Nov 2020 · Paper 62 · Question 4
0620
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The question as text
Brass is a mixture of two metals, copper and zinc. Copper does not react with dilute sulfuric acid. Zinc reacts with hot dilute sulfuric acid to form the soluble salt zinc sulfate. Plan an investigation to find the percentage by mass of zinc in a sample of brass. In your answer you should include how to calculate the percentage by mass of zinc. You have access to normal laboratory apparatus. [6]
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Any 6 from:
weigh brass / known mass of brass
add (dilute) sulfuric acid and heat / hot / warm
excess acid
filter
wash and dry residue / solid
weigh (copper) residue / solid (copper)
percentage zinc calculated correctly
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