a,
$1N= 1,6605.10^{-24}$ phân tử = $1 mol$
$m_{hh}=m_{O_2}+m_{CO_2}+m_{N_2}=0,5.32+2,5.44+0,25.28=133g$
$V_{hh}=22,4(0,5+2,5+0,25)=72,8l$
b,
$n=\dfrac{\text{số phân tử}}{6.10^{23}}$
$\Rightarrow n_{H_2}=1 (mol), n_{N_2}=0,25 (mol), n_{NH_3}=0,5 mol$
$m_{hh}=1.2+0,25.28+0,5.17=18,34g$
$V_{hh}=22,4(1+0,25+0,5)=39,2l$