Determine whether each of the following will form a solution that is acidic, basic, or pH-neutral.

Question

Determine whether each of the following will form a solution that is acidic, basic, or pH-neutral.

C₂H₅NH₃NO₃

FeCl₃

K₂SO₄

NaHSO₄

Ca(NO₂)₂

(CH₃CH₂)₂NH

Answer 1

The general rule of thumb to follow for these questions is the following:

A salt formed from a strong acid + strong base = neutral pH

A salt formed from a strong acid + weak base = acidic pH

A salt formed from a weak acid + strong base = basic pH

A salt formed from a weak acid + weak base = pH depends on Ka and Kb of the reactants

C₂H₅NH₃NO₃ - formed from weak base (C2H5NH2) + strong acid (HNO3) = acidic solution

FeCl₃ - formed from strong acid (HCl) + weak base (Fe(OH)₃) = acidic solution

K₂SO₄ - formed from strong acid (H₂SO₄) + strong base (KOH) = neutral solution

NaHSO₄ - formed from partial reaction of strong acid + strong base (NaOH) = acidic salt

Ca(NO₂)₂ - formed from weak acid (HNO₂) + strong base (Ca(OH)₂) = basic solution

(CH₃CH₂)₂NH - diethyl amine = basic solution (this is a weak base not reacted with anything)