Question

Calculate the melting point of a 0.120 m iron(iii) chloride solution

Answer 1

freezing point of water =0 degree celsius
∆t=kf x m x i(vant hoff factor)
kf=1.86 for water
m=0.120
i=3 for fecl3
∆t=6.696 C
freezing temp= 0-6.696
=-6.696 C

Answer 2

Given,

Concentration of FeCl₃ solution = 0.120 M

To find,

The melting point of the solution

Solution,

The melting point of the solution of iron III chloride is -0.6696 degrees Celsius.

We can simply solve the numerical problem by the following procedure.

We know that,

The concentration of FeCl₃ solution = 0.120 M

The vant off factor of the solution = 3.

The freezing point of water = 0 degrees Celsius

Kf of water = 1.86

Now,

We know by a formula that,

Change in temperature = Kf x i x m

                                         = 1.86 x 3 x 0.120

                                         = 0.6696

But,

The freezing point of water = 0 degrees Celsius

Thus,

The melting point of the iron chloride solution = 0 - 0.6696

                                                                          = - 0.6696 degrees Celsius

As a result,

The melting point of the solution of iron III chloride is -0.6696 degrees Celsius.