1)
容积V=装满水后水的体积=水的质量/水的密度=(700g-200g)/(1g/cm^3)=500cm^3
2)
ρ酒精=0.8×10^3kg/m3=0.8g/cm^3
m=p酒精*V=0.8g/cm^3*(500cm^3)=400g