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Question
Predict whether van’t Hoff factor, (i) is less than one or greater than one in the following:
CH3COOH dissolved in water
Solution
van't hoff factor i = `"total number of moles of particles after dissociation association"/"no.of moles of particls before association dissociation"`
(i) CH3COOH
\[\ce{CH3\underset{1}{C}OOH->[H2O]CH3\underset{1}{C}OO- \underset{+1 = 2}{+H+}\text{(dissociation)} }\]
`i = 2/1 =2 ` (i is greater 1)
(ii) CH3COOH dissolved in benzene
\[\ce {2C\underset{2}{H}3COOH ->[benzene]\underset{1\text{(due to H-bonding)}}{CH3COOH}2}\] (association)
1(due to H-bonding)
`i= 1/2=0.5` (i is less than 1)
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