* Calcium chloride (CaCl₂) - a soluble salt
* Ammonia (NH₃) - a gas with a pungent odor
* Water (H₂O) - a liquid
The balanced chemical equation for this reaction is:
Ca(OH)₂ (aq) + 2NH₄Cl (aq) → CaCl₂ (aq) + 2NH₃ (g) + 2H₂O (l)
Here's a breakdown of what happens:
1. Dissolution: Both calcium hydroxide and ammonium chloride dissolve in water, forming their respective ions:
* Ca(OH)₂ → Ca²⁺ + 2OH⁻
* 2NH₄Cl → 2NH₄⁺ + 2Cl⁻
2. Ion Exchange: The calcium ions (Ca²⁺) from calcium hydroxide react with the chloride ions (Cl⁻) from ammonium chloride, forming calcium chloride (CaCl₂), which remains dissolved in the solution.
3. Formation of Ammonia: The hydroxide ions (OH⁻) from calcium hydroxide react with the ammonium ions (NH₄⁺) from ammonium chloride. This reaction produces ammonia gas (NH₃) and water (H₂O).
4. Gas Evolution: The ammonia gas, being less soluble in water, escapes into the atmosphere, giving off a characteristic pungent odor.
Observations:
* You would observe the solution becoming cloudy as calcium hydroxide dissolves.
* You would also notice a distinct ammonia smell, which intensifies as the reaction progresses.
* The solution might heat up slightly due to the exothermic nature of the reaction.
Overall, the reaction between calcium hydroxide and ammonium chloride is a classic example of a double displacement reaction leading to the formation of a gas and a salt.
