Question

The background information provided for this lab stated “ΔTf in, °C, at very low concentrations (is) given by the equation: ΔTf = kf•m.” Why is this equation only true for low concentrations? What phenomena are not being accounted for?

**Please dumb down the explanation, so it is easy to understand. Thank you.

Answer 1

At low concentration , means low amounts of solute (diluted solution) it is believed that solute is completely dissociated and its Vant's Hoff factor is considered to be unity .

That is why , dTf = Kf × m (at low concentration) .

Here we are not accounting the Vant's Hoff factor (i) of solute .

If we consider Vant's Hoff factor then ;

dTf = i × Kf × m

For low concentration , i = 1 , so dTf = Kf × m

That is why this equation is true only for low concentrations.