p(O2) n(O2) 0.180 ×35.5kPa=200kPa 0.320 机邵学电國图 p(N2)=p-p(NH3)-p(O2) (133.0-35.5-20.0)kPa =77. kpAp(N2 )= p- p(NH3 ) - p(O2 ) =(133.0-35.5-20.0)kPa =77.5kPa p n n p (O ) (O ) 2 2 = 35.5kPa 20.0kPa 0.320 0.180 =  =