An aqueous solution of ________ will produce an acidic solution.

Question

A. KNO₃ 

B. NH₄NO₃

C. Na₂SO₃ 

D. RbBr

E. Mg(ClO₄)₂ 

Answer 1

B. NH₄NO₃ and E. Mg(ClO₄)₂ 

The reason is that these salts are a result of the reaction of a weak base and a strong acid (NH4OH and HNOE; Mg(OH)₂ and HClO₄). All other options are the salts of either a strong acid and strong base (A, D), or a strong base and weak acid (C). NOTE: some might suggest that Mg(OH)₂ is a strong base and thus E. Mg(ClO₄)₂ would be neutral, but in fact, Mg(OH)₂ is considered a weak base because of its limiting solubility.

A. KNO₃ - neutral pH

B. NH₄NO₃ - acidic pH

C. Na₂SO₃ - basic pH

D. RbBr - neutral pH

E. Mg(ClO₄)₂ - acidic pH