Answer:
The freezing point will be [tex]2.9^{0}C[/tex]
Explanation:
The depression in freezing point is a colligative property.
It is related to molality as:
[tex]Depressioninfreezing point=K_{f}Xmolality[/tex]
Where
Kf= [tex]20\frac{^{0}C}{m}[/tex]
the molality is calculated as:
[tex]molality=\frac{moles_{solute}}{mass_{solvent}}[/tex]
[tex]moles=\frac{mass}{molarmass}=\frac{0.694}{154}=0.0045mol[/tex]
[tex]massofcyclohexane=25g=0.025Kg[/tex]
[tex]molarity=\frac{0.0045}{0.025}=0.18m[/tex]
Depression in freezing point = [tex]20X0.18=3.6^{0}C[/tex]
The new freezing point = [tex]6.5^{0}C-3.6^{0}C=2.9^{0}C[/tex]
