Elevation in boiling point, ΔTb=i×Kb×m.( Kb is constant for a solvent)
If molality (m) is same,ΔTb∝ van’t Hoff factor
(i)CH3COOH only partially dissociates, ∴i<2 NaCl,Na2SO4
and K3PO4 almost completely dissociate to produce 2,3 and 4 ions per formula respectively, ∴i≈2,3, and 4 respectively ∴ The order of i= the order of boiling points =CH3COOH<NaCl<Na2SO4<K3PO4