Question

An experimental alloy contained by copper and tantalum. 3.7950 g of the alloy was dissolved and analyzed gravimetrically. The copper was precipitated and weighed as CuO, a mass of 0.1805 g was obtained. Calculate the %w/w Cu in the alloy. [Answer in 2 decimal places]

Answer 1

Convert 0.1805 g CuO to mass Cu and substitute into the percent formula of
%Cu = (mass Cu/mass sample)*100 = ?

Answer 2

is mass sample 0.1805?

Answer 3

No. Mass sample is 3.7950g.
mass CuO is 0.1805 from the problem.