Question

Which one of the following on hydrolysis, gives the corresponding metallic hydroxide, $ {{H}_{2}}{{O}_{2}} $ and $ {{O}_{2}} $ ?

• A. $ L{{i}_{2}}O $
• B. $ N{{a}_{2}}{{O}_{2}} $
• C. $ Na{{O}_{2}} $
• D. $ N{{a}_{2}}O $
• E. $ BeO $

Answer 1

Answer: (C)

On hydrolysis, alkali metal oxides give the corresponding metallic hydroxides.
$ L{{i}_{2}}O+{{H}_{2}}O\xrightarrow{{}}2LiOH $
$ N{{a}_{2}}O+{{H}_{2}}O\xrightarrow{{}}2NaOH $
The peroxides of alkali metals give the corresponding metallic hydroxide and
$ {{H}_{2}}{{O}_{2}} $ .
$ N{{a}_{2}}{{O}_{2}}+2{{H}_{2}}O\xrightarrow{{}}2NaOH+{{H}_{2}}{{O}_{2}} $
Whereas, the superoxides of alkali metals give the corresponding metallic hydroxide, $ {{H}_{2}}{{O}_{2}} $ and $ {{O}_{2}} $
$ 2Na{{O}_{2}}+2{{H}_{2}}O\xrightarrow{{}}2NaOH+{{H}_{2}}{{O}_{2}}+{{O}_{2}} $
$ Be{{(OH)}_{2}} $ cannot be prepared by hydrolysis of $ BeO, $ as it is insoluble in water.