Question

2 gm of benzoic acid dissolved in 25 gm of benzen showing depression in freezing point kf = 4.9 find Alpha​

Answer 1

Answer:

Given,

WB=2g,Kf=4.9KKgmol−1

WA=25g,ΔTf=1.62K

Now,

ΔTf=Kf×MBWB×WA1000

MB=1.62×254.9×2×1000=241.98g/mol

2C6H5COOH⇌(C6H5COOH)2

If x is the degree of association, (1−x) mole of benzoic acid left undissociated & corresponding x/2 as associated moles of C6H5COOH at equilibrium.

∴ Total number of moles of particles at eqm,

⇒1−x+2x=1−2x=i

⇒i=

Answer 2

Explanation:

99.2 is the correct answer