1
дано
n(O2)=1 mol
n(H2)=1mol
n(Ar)=1mol
решение
m=n*M
m(O2)=n(O2)*M(O2), M(O2) =32g/mol
m(O2)=1*32=32g
m(H2)=n(H2)*M(H2), M(H2)=2g/mol
m(H2) = 1*2=2g
m(Ar)=n(Ar)*M(Ar),M(Ar)=39.9g/mol
m(Ar)=1*39.9=39.9g
ответ 32 гр, 2 гр, 39.9 гр.
2)
M(Ne)=20.179g/mol
M(HF)=1+18.9984g/mol=19.9984g/mol
3)Xe+4 F- , C+4 CL- , P+5 CL-