题目

下列气体分子数一定相等的是 A 等质量等密度的N2和C2H4 B等体积等密度的CO2和C2H4 C 等温等体积的O2和N2 D等压强等提价N2和CO 选什么为什么

提问时间：2020-11-02

答案

A. is the right answer.
n=m/M
m(N2)=m(C2H4) & M(N2)=M(C2H4) --> n(N2)=N(C2H4)
B.
M(CO2)!=M(C2H4)
C.
pV=nRT --> n=pV/(RT)
only T(O2)=T(N2), V(O2)=V(N2) cannot give n is the same.
D.
pV=nRT --> n=pV/(RT)
only p(CO)=p(N2), V(CO)=V(N2) cannot give n is the same.