Chemistry - Mole Concept Question with Solution | TestHub

A mixture of ${\mathrm{H}}_2,{\mathrm{N}}_2$ and ${\mathrm{O}}_2$ occupying 100 ml underwent reaction so as to form ${\mathrm{H}}_2{\mathrm{O}}_2(\mathrm{l})$ and ${\mathrm{N}}_2{\mathrm{H}}_2(\mathrm{g})$ as the only products, causing the volume of contract by 60 ml . The remaining mixture was passed through pyragallol causing a contraction of 10 ml . To the remaining mixture excess ${\mathrm{H}}_2$ was added and the above reaction was repeated, causing a reduction in volume of 10 ml . (No other products are formed)

What is the mole percent of ${\mathrm{N}}_2$ in the initial mixture ?