2.25 g of a Non volatile substance dissolved in 250 g of C_6H_6.This solution shows depression in F.P. by 0.256 K.Which of the following is/are correct : Given that : (K_b and K_f for C_6H_6 is 2.53 "Kmolal"^(-1) and 5.12 "Kmolal"^(-1),BP of C_6H_6=353.3K)

2.25 g of a Non volatile substance dissolved in 250 g of C_6H_6.This s

1.	2.25 g of a Non volatile substance dissolved in 250 g of C_6H_6.This solution shows depression in F.P. by 0.256 K.Which of the following is/are correct : Given that : (K_b and K_f for C_6H_6 is 2.53 "Kmolal"^(-1) and 5.12 "Kmolal"^(-1),BP of C_6H_6=353.3K)
Answer» MOLAR mass of SUBSTANCES is =180 B.P. of solution is =180 Relative lowering in vapour PRESSURE of solvent =0.0038 All are not correct Solution :`DeltaT_f=mxxK_f=(g.wt)/(M.M)xx1000/((g.wt.)_"solvent")xxK_f` 0.256=`2.25/(M.M)xx1000/250xx5.12` M.M=180 g/mol `DeltaT_b=mxxK_b=(g.wt)/(M.M)xx1000/((g.wt.)_"solvent")xxK_b =2.25/(180)xx1000/250xx2.53=0.1265` B.P. of solution =353.3+0.1265=353.425 K `(DeltaV.P.)/P_("solvent")^@=X_B=n_B/(n_A+n_B)=(2.25/180)/(2.25/180+250/75)=0.00388`.