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Two grams of benzoic acid (C(6)H(5)COOH)...

Two grams of benzoic acid `(C_(6)H_(5)COOH)` dissolved in `25.0 g` of benzene shows a depression in freezing point equal to `1.62 K`. Molal depression constant for benzene is `4.9 K kg^(-1)"mol^-1`. What is the percentage association of acid if it forms dimer in solution?

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`{:(2C_6H_5COOH,hArr,(C_6H_5COOH)_2),(" "1,"",""),(" "1-alpha,""," "1-alpha),(i=1-alpha//2,"",""):}`
`DeltaT_f=iK_fm rArr 1.62 =(1-(alpha)/2)xx4.9xx(2//122)/(25//1000)rArr alpha ~~99%`
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