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Question
Which solution has the lower freezing point? 10 g of methanol (CH3OH) in 100g g of water (or) 20 g of ethanol (C2H5OH) in 200 g of water.
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Solution
∆Tf = Kf i.e
∆Tf α m
`"m"_("CH"_3-"OH") = (10/32)/0.1`
= 3.125 m
`"m"_("CH"_3-"OH") = (20/46)/0.2`
= 2.174 m
∴ Depression in freezing point is more in methanol solution and it will have lower freezing point.
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