Từ pV = nRT, thấy rằng khi p giảm 5% thì n giảm 5%.
\(n_{N_2}=a;n_{H_2}=b;n_{N_2pư}=0,1a\\ PT:\dfrac{1}{2}N_2+\dfrac{3}{2}H_2-Fe,t^{^0}->NH_3\\ n_{sau}=0,95\left(a+b\right)=0,1a+0,3a+0,2a=0,6a\\ a=2,714b\\ \%V_{N_2}=\dfrac{a}{a+b}.100\%=73,07\%\\ \%V_{H_2}=26,93\%\)