If 2 mL of acetone is present in 45 mL of its aqueous solution ,calculate the concentration of this solution .

Options

A. 20
B. 40
C. 50
D. 60

Answer

C

Explanation

`AB hArr A^(+) + B^(-)`
Initial `" "1 hArr 0" "0`
At equ. ` 1- alpha " " alpha " " alpha`
Total moles = `1 - alpha + alpha + alpha = 1 alpha`
` I = (1+alpha)/(1)`
` I = ("Observed colligative property")/("Normal colligatve property")`
`= (0.81)/(0.54) = 1.5`
`therefore " " 1 + alpha + = 1.5`
or `" " alpha = 0.5 " " or" " 50%`