Question

Quinine is a natural product extracted from the bark of the cinchona tree, which is native to South America. Quinine is used as an antimalarial agent. When 1.29 g of quinine is dissolved in 25.0 g of cyclohexane, the freezing point of the solution is lowered by 3.30 ?C. The freezing point and Kf constant for cyclohexane can be found here. Calculate the molar mass of quinine.Answer should be in G/mol

Answer 1

Kf constant for cyclohexane = 20.8 C/m

Now, we know $\Delta T = Kf *m$

m = moles of quinone/mass of cyclohexane inKg = (1.29/M)/0.025 ( M is the molar mass of quinine)

3.30 = 20.8 x 1.29/(0.025xM)

M = 325.236 g/mol

If your Kf of cyclohexane is different put that and solve again...you will surely get correct answer...

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