If a 0.192 g sample of copper metal reacts with elemental sulfur to form 0.240 g of the sulfide product, (a) find the percent by mass of copper and sulfur in the product and (b) find the empirical formula of the copper sulfide

Answer 1

0.240g = mss Cu + S compound
-0.192g = mass Cu
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0.048 g = S added to the Cu

%Cu = (mass Cu/mass total)*100 = ?

Take a 100 g sample.
mols Cu = grams/atomic mass Cu
mols S = grams/atomic mass S

Find the ratio of Cu to S with the smaller number being 1.00
Post your work if you get stuck.
%S = (mass S/mass total)*100 = ?