Depression in any solute is known as the colligative property.
Here, ΔTf = kf*m m = molality which is equal to moles of solute per kg solvent
Moles of ethylene glycol = 12.4/62
Molality = 0.2/0.1=2
By substituting we get,
ΔTf = 1.86*2 = 3.72K
Difference in freeezing point = 3.72K ie Depression
Boiling point elevation = ΔTb = Kb*b*i
=0.512*2 = 1.024K
Boiling point of solution = 373+1.024= 374.024k= 101.024deg C
The boiling point increases with increase in ethylene glycol percentage.
The use of ethylene glycol increases boiling point and depresses the freezing point.
It act as a anti freezing agent also and can be keep this in car radiator during summer