When 0.014 mol of a weak acid HA is dissolved in enough water to make 1.0 L of solution, [H⁺] is 1.8 *10^-3 M. Calculate the freezing point of this solution. Assume that the molarity concentration is equal to the molality concentration, and assume ideal behavior. K_f (H₂O) is 1.86°C kg/mol. A) -0.058°C B) -0.029°C C) -0.026°C D) +0.029°C E) +0.026°C

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Quizplus · Accepted Answer

The freezing point depression is calculated using ΔTf = i * Kf * m. Here, i (van't Hoff factor) is approximately 1 since HA is a weak acid and only partially dissociates. m (molality) is 0.014 mol/kg. ΔTf = 1 * 1.86 * 0.014 = 0.026°C. The freezing point is lowered, so the solution's freezing point is -0.029°C.

When 0014 Mol of a Weak Acid HA Is Dissolved in in Enough