Question $3$: At $25C$ the density of $50$ percent by mass ethanol water solution is $0,914\frac{g}{cm3}.$ Given that the partial molar volume of water in the solution is $17\mathrm{.}4\frac{cm3}{\text{m}\text{o}\text{l}}.$ a$-)$ Total volume of solution.

b$-)$ The partial molar volume of ethanol

c$-)$ What is the importance of the partial molar volume.