Label the following reactions as oxidation or reduction reac

Label the following reactions as oxidation or reduction reactions:

a) 1/2 O₂ + H₂O + 2e^- -> 2(OH)^-

b) H₂ + 2(OH)^- -> 2H₂O + 2e^-

Solution

by definition

oxidation is loss of electrons

reduction is gain of electrons

1/2 O2 + H2O + 2e- --> 2 (OH)- reduction reaction

its a reduction reaction since electrons are gained

b)

H2 + 2(OH)- ---> 2 H20 + 2e- oxidation reaction

its a oxidation reaction since electrons are lost