Question

Question: Arrange the following 0.10 M solutions in order from most acidic to most basic.

CaBr₂, KNO₂, HClO₄, HNO₂, HONH₃ClO₄, and NH₄NO₂

Short answer

Answer

Order from most acidic to most basic:

${\text{HClO}}_{\text{4}}{\text{> HNO}}_{\text{2}}{\text{> HONH}}_{\text{3}}{\text{ClO}}_{\text{4}}{\text{> CaBr}}_{\text{2}}{\text{> KNO}}_{\text{2}}\approx {\text{NH}}_{\text{4}}{\text{NO}}_{\text{2}}$

Step-by-step solution

About the Salts

CaBr₂ : Salt of strong acid HBr and strong base ca(OH)₂, (pH=7)

KNO₂ : Salt of weak acid HNO₂ and strong base KOH, (pH>7)

HClO₄ : Strong Acid (pH=1)

HNO₂: Weak Acid (pH more than 1)

HONH₃ClO₄ : Salt of strong acid HClO₄ and weak base HONH₂ (solution acidic)

NH₄NO₂ : Salt of weak acid HNO₂ and weak base NH₃ (solution neutral)

pH Order

Order from most acidic to most basic:

${\text{HClO}}_{\text{4}}{\text{> HNO}}_{\text{2}}{\text{> HONH}}_{\text{3}}{\text{ClO}}_{\text{4}}{\text{> CaBr}}_{\text{2}}{\text{> KNO}}_{\text{2}}\approx {\text{NH}}_{\text{4}}{\text{NO}}_{\text{2}}$