One mole of ammonia was completely absorbed in 1L solution each ofI. 1MHC1 II. 1 M CH3COOH andIII. 1 M H2SO4 at 298 KThe decreasing order for the pH of the resulting solution is (given, Kb ( NH3 ) = 4.74

Acids which are weak in water will be highly acidic in NH3. (a) HCl+NH3⇌NH4Cl  (b) CH3COOH+NH3⇌CH3COONH4  (c) H2SO4+NH3⇌NH42SO4 .'. Effect of ammonia is least in H2SO4 and maximum in CH3COOH. ∴ Order of acidic strength of resulting solution is  NH42SO4>NH4Cl>CH3COONH4 ∴ Order of pH of resulting solution is  CH3COONH4>NH4Cl>NH42SO4 Hence, correct option is II > I > III