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02/10/2020 10:33 am
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Exactly 1 g of urea dissolved in 75 g of water gives a solution that boils at 100.114°C at 760 torr. The molecular weight of urea is 60.1. The boiling point elevation constant for water is
(a) 1.02
(b) 0.51
(c) 3.06
(d) 1.51
1 Answer
1
02/10/2020 10:37 am
(b) 0.51
Explanation:
Weight of solute (w) = 1 g
Weight of solvent (W) = 75 g
Boiling point of solution = 100.114°C
Boiling point of solvent = 100°C
ΔT = 100.114 – 100 = 0.114°C
Molecular weight of solute (m) = 60.1
Boiling point elevation constant (K) = ?
m = (1000 x K x w)/ΔT x W
K = (m x ΔT x W)/ 100 x w
= (60.1 x 0.114 x 75)/1000 x 1
= 513.8/1000 = 0.513