${H_2}{O_2}\, + \,{H_2}O\, \rightleftharpoons \,{H_3}{O^ + }\, + \,HO_2^ - $
$(A)\,ZnO + Na_2O\rightarrow Na_2ZnO_2$
$(B)\,ZnO + CO_2\rightarrow ZnCO_3$