General Chemistry/Reactions of Acids and Bases/Answers

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Answers to Reactions of Acids and Bases[edit]

\hbox{HPO}_4^{2-} + \hbox{OH}^- \to \hbox{PO}_4^{3-} + \hbox{H}_2\hbox{O} 1. Equimolar solutions of sodium biphosphate and potassium hydroxide are mixed.
\hbox{HPO}_4^{2-} + \hbox{H}^+ \to \hbox{H}_2\hbox{PO}_4^- 2. Equimolar solutions of sodium biphosphate and hydrochloric acid are mixed.
\hbox{SO}_2 + \hbox{OH}^- \to \hbox{HSO}_3^-

\hbox{HSO}_3^- + \hbox{H}^+ \to \hbox{H}_2\hbox{SO}_3

3. Excess sulfur dioxide gas is bubbled into a dilute solution of sodium hydroxide. Acid is then added.
\hbox{Al}^{3+} + 3\hbox{H}_2\hbox{O} \to \hbox{Al}(\hbox{OH})_3 + 3\hbox{H}^+ 4. Aluminum chloride is dissolved into water.
\hbox{NaF} + \hbox{H}_2\hbox{O} \to \hbox{Na}^+ + \hbox{OH}^- + \hbox{HF}

\hbox{H}^+ + \hbox{OH}^- \to \hbox{H}_2\hbox{O}

5. Sodium fluoride is dissolved into water. Strong acid is then added.
\hbox{SO}_3 + \hbox{CaO} \to \hbox{CaSO}_4

Neutral. Ca2+ is the conjugate of a strong base and SO42- is the conjugate of a strong acid.

6. Solid calcium oxide is exposed to a stream of sulfur trioxide gas. If the resulting compound is dissolved, will the solution be acidic, basic, or neutral?
\hbox{HCl} + \hbox{Ag}^+ \to \hbox{H}^+ + \hbox{AgCl}

A cloudy precipitate forms, as silver chloride is not soluble.

7. Gaseous hydrogen chloride is bubbled into a solution of silver nitrate.
\hbox{NH}_4^+ + \hbox{OH}^- \to \hbox{NH}_3 + \hbox{H}_2\hbox{O}

Gas bubbles form.

8. Ammonium chloride crystals are dissolved in water. Sodium hydroxide is then added.
\hbox{HCO}_3^- + \hbox{Ca}^{2+} + \hbox{OH}^- \to \hbox{H}_2\hbox{O} + \hbox{CaCO}_3

A cloudy precipitate forms, as calcium carbonate is not soluble.
Hint: The hydroxide reacts with the bicarbonate to form water, then the resulting carbonate reacts with calcium.

9. Calcium hydroxide crystals are dissolved into a solution of sodium bicarbonate.
\ddot{\hbox{P}}\hbox{H}_3 + \hbox{AlCl}_3 \to \hbox{H}_3\hbox{P}-\hbox{AlCl}_3

They have formed a Lewis adduct. Aluminum chloride is a very strong Lewis acid.
Phosphine is a Lewis base because there is a non-bonding pair of electrons on the P that can be donated.

10. Phosphine gas is sprayed onto pebbles of aluminum trichloride.