Question

The freezing point of 0.1 m aqueous solution of urea, if K_f for water is 1.86 K kg mol⁻¹ is ______.

Options

• 1.86°C

• −1.86°C

• 0.186°C

• −0.186°C

Answer 1

The freezing point of 0.1 m aqueous solution of urea, if K_f for water is 1.86 K kg mol⁻¹ is −1.86°C.

Explanation:

ΔT_f = k_f × m

= 1.86 × 0.1

= 0.186

ΔT_f = `T_f^0 - T_f`

0.186 = 0 − T_f

T_f = −0.186