Question

In a solution with carbon tetrachloride as the solvent, the compound VCl4 undergoes dimerization: 2VCl4 34 V2Cl8 When 6.6834 g of VCl₄is dissolved in 100.0 g of carbon tetrachloride, the freezing point is lowered by 5.97˚C.

Calculate the value of the equilibrium constant for the dimerization of VCl₄ at this temperature. (The density of the equilibrium mixture is 1.696 g/cm3, and Kf = 29.8˚C kg/mol for CCl4.)

Short answer

The value of the equilibrium constant is ΔTf = 10.44

Step-by-step solution

Step 1:

First to calculate moles of VCl4 = 6.6834 g VCl4 x 1mol of VCl4/ 192.74 g VCl4

= 3.46 x 10 ^-2 mol VCl4

29.8 + 273 = 302.8 K

5.97 + 273 = 278.97

ΔTf = Kf . m = 302.8 x 3.46 x 10 ^-2= 10.44