Arrange the following in increasing order of pH
KNO3 (aq), CH3COONa (aq), NH4Cl (aq), C6 H5COONH4 (aq)
pH-: It is defined as the negative logarithm to base 10 of the hydrogen ion of that solution.
i. KNO3 –it is a salt of strong acid (HNO3)-strong base (KOH), it does not dissociate into H+ or OH-when dissolved into the water so it remains neutral. We know that neutral compounds have a pH of 7.
ii. CH3COONa –it is a salt of a weak acid (CH3COOH) and strong base (NaOH) so its aqueous solution will be basic i.e. pH > 7.
iii. NH4Cl- it is a salt of a strong acid (HCl) and a weak base (NH4OH). So the aqueous solution will be acidic i.e. pH<7
iv.C6H5COONH4 –it is a salt of a weak acid (benzoic acid) and weak base (NH4OH) so its aqueous solution will be having pH equal to 7 but slightly less than 7.
The increasing order of pH will be;
CH3COONa< KNO3< C6H5COONH4<NH4Cl