Answer:
The first one among the four attached graphs correctly shows the effect on the freezing point caused by increasing the molality of a solution
Explanation:
According to colligative property of molecules- [tex]\Delta T_{f}=k_{f}.m[/tex]
where [tex]\Delta T_{f}[/tex] is the depression in freezing point [tex](F_{p})[/tex]
[tex]k_{f}[/tex] is cryogenic constant of solvent and m is molality of solution
As [tex]k_{f}[/tex] is constant for a certain solvent therefore the above relation is similar to linear equation y=mx. here y represents [tex]\Delta T_{f}[/tex] and x represents m
So a graph between [tex]\Delta T_{f}[/tex] and m would give straight line passing through origin
If we extrapolate the first graph by joining all the points then it will give a straight line passing through origin.
Hence the first graph is the correct one depicting change in freezing point with molality
