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Molecules of benzoic acid (C_6 H_5 COOH) dimerise in 30 g of benzene. ' w ' g of benzoic acid shows a depression in freezing point equal to 2 K. If…

JEE Main 2019 — Chemistry Physical Chemistry

2019mcqmedium

Molecules of benzoic acid (C6H5COOH)({C}_{6}{H}_{5}\mathrm{COOH})(C6​H5​COOH) dimerise in 30g30 g30g of benzene. ' www ' ggg of benzoic acid shows a depression in freezing point equal to 2K2 K2K. If the percentage association of the acid to form dimer in the solution is 808080, then www is: ((( Given that Kf=5Kmol−1{K}_{f}=5{\mathrm{Kmol}}^{-1}Kf​=5Kmol−1, molar mass of benzoic acid =122gmol−1)=122 {\mathrm{gmol}}^{-1})=122gmol−1)

Official previous-year question

Held on 12 Jan 2019 · Verified 6 Jul 2026.

Options

  1. A

    1.0g1.0 g1.0g

  2. B

    2.4g2.4 g2.4g

  3. C

    1.8g1.8 g1.8g

  4. D

    1.5g1.5 g1.5g

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