When copper(II) oxide is heated in hydrogen gas, the following reaction takes
place.
$$
\mathrm{CuO}(s)+\mathrm{H}_{2}(g) \longrightarrow
\mathrm{Cu}(s)+\mathrm{H}_{2} \mathrm{O}(g)
$$
A copper rod coated with copper(II) oxide has a mass of \(38.72 \mathrm{~g}\).
The rod is heated and made to react with \(5.67 \mathrm{~L}\) of hydrogen gas,
whose density at the conditions of the experiment is \(0.0519 \mathrm{~g} /
\mathrm{L}\).
(a) How many grams of \(\mathrm{CuO}\) were converted to Cu?
(b) What is the mass of the copper after all the hydrogen is consumed? (Assume
that \(\mathrm{CuO}\) is converted only to Cu.)