Question

Copper forms two oxides. For the same amount of copper, twice as much oxygen was used to form the first oxide than to form the second one. What is the ratio of the valencies of copper in the first and second oxides?

Answer 1

$Cu$ forms $2$ oxides, $CuO$ & $C{u}_{2}O$

(1) $CuO⟶63.5$ parts of $Cu$ reacts with $16$ parts of oxygen

(2) $C{u}_{2}O⟶63.5$ parts of $Cu$ reacts with $8$ parts of oxygen

$\therefore$ Ratio of their valencies$=16:8$

$=2:1$