Phenol dimerised to $60\%$ in a solvent. The observed molecular weight of phenol will be

Pure benzene freezes at $5.3^oC$. $A$ solution of $0.223 \ g$ of $C_6H_5CH_2COOH$ in $4.49 \ g$ of benzene freezes at $4.47^oC$. Given $K_f = 5.12 \ K \ kg/mol$,what can be concluded from this?

When substance $A$ is dissolved in solvent $B$,it associates to form $A_3$. The van't Hoff factor $i$ is:

One molal solution of a carboxylic acid in benzene shows the elevation of boiling point of $1.518 \ K$. The degree of association for dimerization of the acid in benzene is $........ \%$. ($K_b$ for benzene $= 2.53 \ K \ kg \ mol^{-1}$)

If $0.15 \ m$ aqueous solution of $KCl$ freezes at $-0.51^{\circ} C$,calculate the van't Hoff factor of $KCl$ (cryoscopic constant of water is $1.86 \ K \ kg \ mol^{-1}$).

$2 \,g$ of benzoic acid $(C_{6}H_{5}COOH)$ dissolved in $25 \,g$ of benzene shows a depression in freezing point equal to $1.62 \,K$. The molal depression constant for benzene is $4.9 \,K \,kg \,mol^{-1}$. What is the percentage association of the acid if it forms a dimer in the solution?