Question

What is the percentage by mass of copper in copper oxide (CuO)?

Answer 1

79.89%

Step-by-step explanation:

Copper has a molar mass of 63.55

Oxygen has a molar mass of 16.00

If you add these you get 79.55

To get the mass percent of copper divide copper by the whole. 63.55/79.55*100= 79.89%