Question

2.2 How many grams CuO would 1.00 g Paris green, Cu3(As03)2 2A$203- Cu/C2H302)2, give?

Answer 1

There are 4 moles of Cu per mole of Paris Green, which means that the amount of CuO moles obtained from the decomposition will be 4 times the number of moles of Paris Green that were decomposed.
The molar mass of Paris Green is 1013.8 g/mol, so the number of initial moles is:

$n=\frac{m}{m_{molar}}=\frac{1.00g}{1013.8g/mol}=9.86x10^{-4}moles$

The number of moles of CuO produced from the decomposition is 4 times this, which is: 3.95x10^-3 moles. This number represents a mass of (the molar mass of CuO is 79.55 g/mol):

$m=n\cdot m_{molar}=3.95^{-3}moles\cdot 79.55\frac{g}{mol}=0.314\: g$