Acetic acid associates in benzene to form a dimer. `1.65 g` of acetic acid when dissolved in `100 g` of benzene raised the boiling point by `0.36^(@)C`. Calculate the Van't Hoff factor and degree of association of acetic acid.
(`K_(b)` for benzene=`2.57^(@)C`)

Explanation

`2CH_3COOHhArr(CH_3COOH)_2`
Intial moles 1.65/60 0
At equilibrium `1.65/60(1-alpha)` `1.65/60alpha/2`
Total moles at equilibrium `=1.65/60(1-alpha/2)`
`DeltaT_b=K_bxxm,0.36=2.57xx1.65/60(1-alpha/2)`
`alpha=0.981`
`"Van't Hoff factor"=("np. of moles at equilibrium")/("Intial no. of moles")=i`
`i=1-alpha/2=0.5`