In a reaction container,100 g of hydrogen and 100 g of Cl₂ are mixed for the formation of
HCl gas .What is the limiting reagent and how much HCl is formed in the reaction ?

$\underset{2\mathrm{g}}{{\mathrm{H}}_2}+\underset{71\mathrm{g}}{{\mathrm{Cl}}_2}\to \underset{73\mathrm{g}}{2\mathrm{HCl}}$
2 g of $H_2$ react with 71 g of ${\mathrm{Cl}}_2$
100 g of $H_2$ will react with $\frac{71}{2}\times 100=3550\mathrm{g}\text{ of }{\mathrm{Cl}}_2$
Hence, ${\mathrm{Cl}}_2$ is the limiting reagent. 
71 g of ${\mathrm{Cl}}_2$ produce 73 g of HCl 
100 g of ${\mathrm{Cl}}_2$ will produce $\frac{73}{71}\times 100=102.8\mathrm{g}\text{ of }\mathrm{HCl}$