Chemistry - Mole Concept Question with Solution | TestHub

Key Idea (i) ${\mathrm{H}}_2+\frac{1}{2}{\mathrm{O}}_2⟶{\mathrm{H}}_2\mathrm{O}$ (ii) Amount of water produced is decided by limited reactant (ie, the reactant which is used in small amount) $$\begin{array}{rl}& {\mathrm{H}}_2+\frac{1}{2}{\mathrm{O}}_2⟶{\mathrm{H}}_2\mathrm{O}\\ & 1\mathrm{mol}\frac{1}{2}\mathrm{mol}1\mathrm{mol}\\ & \frac{10}{2}\mathrm{mol}\frac{64}{32}\mathrm{mol}\\ & =5\mathrm{mol}=2\mathrm{mol}\\ & \because \frac{1}{2}{\mathrm{molO}}_2\text{ gives }=1\mathrm{mol}{\mathrm{H}}_2\mathrm{O}\\ & \therefore 2\mathrm{mol}{\mathrm{O}}_2\text{ will give }=1\times 2\times 2=4\mathrm{mol}.\end{array}$$