Cyclohexane has a freezing point of 6.50 ∘C and a Kf of 20.0 ∘C/m. What is the freezing point of a solution made by dissolving 0.771 g of biphenyl (C12H10) in 25.0 g of cyclohexane?

Explanation:

Depression in freezing point is:

where,

= freezing point of solution = ?

=  freezing point of solvent (cyclohexane) =

=  freezing point constant  of  solvent (cyclohexane)  =

m = molality

i = Van't Hoff factor = 1 (for non-electrolyte)

= mass of solute (biphenyl) = 0.771 g

= mass of solvent (cyclohexane) = 25.0 g

= molar mass of solute (biphenyl) =

Now put all the given values in the above formula, we get:

Therefore, the freezing point of a solution made by dissolving 0.771 g of biphenyl in 25.0 g of cyclohexane is