Chemistry - Complete Pblock- Question with Solution | TestHub

Among the following, the number of reactions evolve dioxygen $\left(0_2\right)$ gas as one of the products is $\_\_\_\_$.

(1) ${\mathrm{KO}}_2+{\mathrm{H}}_2\mathrm{O}\to$

(2) ${\mathrm{Pb}}_3{\mathrm{O}}_4+{\mathrm{HNO}}_3\to$

(3) ${\mathrm{H}}_2{\mathrm{O}}_2+{\mathrm{I}}_2+{\mathrm{OH}}^{-}\to$

(4) ${\mathrm{F}}_2+{\mathrm{H}}_2\mathrm{O}\to$

(5) ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_{7(\mathrm{s})}\stackrel{\Delta }{\to }$

(6) $\mathrm{HOCl}+{\mathrm{H}}_2{\mathrm{O}}_2\to$

(7) ${\mathrm{Na}}_2{\mathrm{O}}_{2(\mathrm{s})}+{\mathrm{CO}}_2\to$