# Problem: Sulfuric acid in water dissociates completely into H+ and HSO4- ions. The HSO4- ion dissociates to a limited extent into H+ and SO42-. The freezing point of a 0.1000 m solution of sulfuric acid in water is 272.72 K.Calculate the molality of SO42- in the solution, assuming ideal solution behavior.

###### FREE Expert Solution

We’re being asked to find the molality of SO42- solution assuming ideal behavior.

When calculating the freezing point of a solution, we’re going to use the equation for Freezing Point Depression.

$\overline{){\mathbf{∆}}{{\mathbf{T}}}_{{\mathbf{f}}}{\mathbf{=}}{\mathbf{i}}{\mathbf{·}}{{\mathbf{K}}}_{{\mathbf{f}}}{\mathbf{·}}{\mathbf{m}}}$

∆Tf = change in freezing point = Tf pure solvent –Tf solution
Kf = freezing point depression constant
i = van' t Hoff factor of the solute = no. of ions
m = molality

Recall that the formula for molality is:

Determine the required values for the Freezing Point Depression equation:

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###### Problem Details

Sulfuric acid in water dissociates completely into H+ and HSO4- ions. The HSO4- ion dissociates to a limited extent into H+ and SO42-. The freezing point of a 0.1000 m solution of sulfuric acid in water is 272.72 K.

Calculate the molality of SO42- in the solution, assuming ideal solution behavior.

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Freezing Point Depression concept. If you need more Freezing Point Depression practice, you can also practice Freezing Point Depression practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Mutambuki's class at OKSTATE.