Question

Electrolysis of water to form hydrogen and oxygen gas is called __________.

• A. precipitation
• B. oxidation-reduction
• C. distillation
• D. hydration
• E. condensation

Answer 1

The correct option is B oxidation-reduction

Electrolysis of water to form hydrogen and oxygen gas is called oxidation-reduction.
$2H_{2}O\to 2H_2+O_2$
Hydrogen ions (protons) are reduced.
$2H^{+}+2e^{-}\to H_2$
Hydroxide ions are oxidised.
$4O{H}^{-}\to 2H_{2}O+O_2+4e^{-}$