What is the volume of ethyl alcohol (density 1.15 g/cc) that has to be added to prepare 100 cc of 0.5 M ethyl alcohol solution in water ?

Options

A. `1.15c c`
B. `2c c`
C. `2.15c c`
D. `2.30c c`

Answer

B

Explanation

`" Molarity "=("mass"xx1000)/(" molecular weight " xx" volume of solution ")`
Molecular weight of ethyl alohol, `C_(2)H_(5)OH=46g" mol"^(-1)`
`0.5M=("mass"xx1000)/(46xx100)`
`rArr"mass"=2.3g`
`:.` Volume of ethyl alcohol required,
`V(" mass of ethyl alcohol ")/("demsity of ethyl alcohol")`
`(2.3g)/(1.15g//c c)=2c c`