Question

What is the unit of cryoscopic constant?

Options

• K kg dm^-3 

• K Kg dm³ 

• K kg mol

• K kg mol^-1

Answer 1

K kg mol^-1 

Explanation:

cryoscopic constant `("K"_"f") = (Delta "T"_"f")/"m"`

where, `Delta "T"_"f"` = depression in freezing point,

m = molality

Then, unit of `"K"_"f" = "K"/"Molal" = "K"/("mol kg"^-1)` = K kg mol^-1