ΔTf is maximum when i×m is maximum.1) m1=60180=3,i=1+αHence ΔTf=(1+α)⋅kf=3×1.86=5.58∘C(α<<1) 2) m2=60180=3,i=0.5,ΔTf=23×kf′=7.68∘C 3) m3=122180=1.48,i=0.5,ΔTf=21.48×kf′=3.8∘C 4) m4=180180=1,i=1,ΔTf=1⋅kf′=1.86∘C As per NCERT, kf′(H2O)=1.86K⋅kgmol−1kf′(Benzene)=5.12K⋅kgmol−1