Question

Density of `2.05 M` solution of acetic acid in water is `1.02g//mL`. The molality of same solution is:
A. `0.44 "mol" kg^-1`
B. `1.14 "mol" kg^-1`
C. `3.28 "mol" kg^-1`
D. `2.28 "mol" kg^-1`

Answer 1

Correct Answer - D
Weight of acetic acid `= 2.05 xx 60 = 123`
Weight of solution `= 1000 xx 1.02 = 1020`
`:.` Weight of water `= (1020 - 123) = 897 g`
`:.` Molality `= (2.05 xx 1000)/(897) = 2.285`.