If the degree of dissociation of aqueous solution of weak monobasic acid is determined to be 0.3, then the observed freezing point will be _______ % higher than the expected/theoretical freezing point. (Nearest integer).

For a weak monobasic acid with degree of dissociation $$\alpha = 0.3$$:

$$HA \rightleftharpoons H^+ + A^-$$

The van't Hoff factor: $$i = 1 + \alpha = 1 + 0.3 = 1.3$$

The observed freezing point depression: $$\Delta T_f = i \cdot K_f \cdot m$$

The expected (without dissociation): $$\Delta T_{f,expected} = K_f \cdot m$$

The observed depression is $$i = 1.3$$ times the expected depression.

The observed depression is $$(1.3 - 1)/1 \times 100 = 30\%$$ higher than expected.

The observed freezing point depression will be 30% higher than expected.