'A' + H2O NaOH; 'A' B NaOH + O2<br>B is used for oxygenating in submarine. A and B are : — s Block Elements Chemistry Question

Question

'A' + H2O $\rightarrow$ NaOH; 'A' $\xrightarrow{\text{O}_2, 400^\circ\text{C}}$ B $\xrightarrow{\text{H}_2\text{O at } 25^\circ\text{C}}$ NaOH + O2<br>B is used for oxygenating in submarine. A and B are :