80g....................................x............
NaOH+NH4Cl=>NH3+H2O+NaCl
40g...................................18 g..........
omega=m(subs)/m(sol)*100%
m(subs)=omega*m(sol)/100%=40%*200g/100%=80g
x=m(H2O)=80g*18g/40g=36g
niu(H2O)=m/M=36g/18g/mol=2mol
V(H2O)=2mol*22,4l/mol=44,8l