When copper(II) oxide is heated in the presence of hydrogen gas, elemental copper and water are produced. What mass of copper can be obtained if 34.0 g copper(II) oxide is used?

Answer 1

CuO + H2 ==> Cu + H2O
mols CuO = grams/molar mass
Using the coefficients in the balanced equation, convert mols CuO to mols Cu.
Then g Cu = mols Cu x atomic mass Cu.

Answer 2

Cu2O+2H2=Cu+2H2O