Predict whether the reaction of equal amounts of each of the following acids and bases will yield an acidic, a basic, or a neutral solution. Explain your answer for each.

Question

a.)sulfuric acid, H2SO4 and ammonia, NH3

b.) formic acid, HCOOH and potassium hydroxide, KOH

c.)nitric acid, HNO3 and calcium hydroxide, Ca(OH)2

Answer 1

In the three situations listed above, the answer will depend on whether the reactants are a strong acid + a strong base, a weak acid + a strong base, or a weak base + a strong acid.

In (a), we have a a strong acid + weak base. The resulting solution will be acidic. In (b) you have a weak acid + strong base so the solution will be basic. In (c) we have a strong acid + strong base & the solution will be neutral. A caution here: it says equal "amounts". In (c) if you used equal amounts (which would imply moles or molarities) the result would not be neutral, but basic because there's 2 moles of OH^- per mole of H⁺. Now, if we used equivalent amount, the result be neutral.

The reason that (a) gives an acidic solution is because the conjugate acid of NH₃, NH₄⁺ hydrolyzes and the resulting solution will have an excess of hydronium ions, thus acidic. A caution here again like the one I stated for (c). The molar ration of sulfuric acid to ammonia is 1:2. So equal "amounts" is a poorly stated implication.

In (b) there's no issue with the stoichiometry, it's 1:1. So the resulting solution is basic because the conjugate base of acetic acid, namely the acetate ion, will hydrolyze and produce OH^- ions and the solution is basic.