If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water `(triangleT_f)` when 0.01 mol of sodium sulphate is dissolved in 1 kg of water is `("Given K"_f="1.86K mol"^(-1))`

Options

A. 0.0186K
B. 0.0372K
C. 0.0558K
D. 0.0744K

Answer

C

Explanation

The expression for `Delta T_(f)` is
`Delta T_(f)= ixx K_(f) xx m`
For the reaction `Na_(2)SO_(4) rarr 2Na^(+) + SO_(4)^(2-), i=2 + 1=3`. Hence, `Delta T_(f)= 3 xx 1.86 xx (0.01//1)= 0.0558K`