Solid calcium hydroxide is stirred into an aqueous solution containing ammonium…
CHEMISTRY · Multi-part · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Solid calcium hydroxide is stirred into an aqueous solution containing ammonium chloride according to the balanced molecular equation
Ca(OH)2(s)+2NH4Cl(aq)→2NH3(g)+CaCl2(aq)+2H2O(l)
A pungent gas is released, and the solid completely dissolves.
(a) Write the net-ionic equation for the reaction that occurs in solution.
(b) Identify each type of exchange that occurs in the reaction (proton, electron, and/or ion). Support each identification with specific evidence from your net-ionic equation.
(c) Explain why the reaction can be classified simultaneously as an acid–base process and a gas-evolution process, but not as a redox or precipitation process. In your explanation, refer to changes (or lack of changes) in oxidation numbers, solubility considerations, and the stability of the molecular products formed.
(d) Predict qualitatively whether the equilibrium for this reaction lies far to the right or to the left when all reactants and products are in aqueous solution at standard conditions. Justify your prediction in terms of the physical state and relative stability of the products formed.