A mixture of `NH_(3(g))` and `N_(2)H_(4_((g)))` is placed in a sealed container at `300 K`. The total pressure is `0.5 atm`. The container is heated to `1200 K`, at which time both substances decompose completely according to the equations:
`2NH_(3(g))rarrN_(2(g))+3H_(2(g))`
`N_(2)H_(4_((g)))rarrN_(2(g))+2H_(2(g))`
After decomposition is complete, the total pressure at `1200 K` is found to be `4.5 atm`. Find the amount (mole) per cent of `N_(2)H_(4(g))` in the original mixture.

Answer

`25%`;