(1)X2O5物质的量=0.5/5=0.1molX相对原子质量=(108-16*5)/2=14(2)n(A)=V/22.4 molm(A)=MV/22.4 gm(溶液)=100+MV/22.4 gV(溶液)=(100+MV/22.4)/p cm^3=(0.1+MV/22400)/p Lc=n/V=pV/(2.24+MV/1000) mol/L