When barium hydroxide reacts with ammonium chloride, it undergoes a double displacement gas evolution reaction, producing barium chloride, ammonia gas, and water. This reaction is notably endothermic, meaning it absorbs heat from its surroundings.
Reaction Overview
The chemical interaction between barium hydroxide (Ba(OH)₂) and ammonium chloride (NH₄Cl) is a classic example of a double displacement reaction that also involves the evolution of a gas. It is specifically characterized as an endothermic process, absorbing energy from the environment, which can lead to a noticeable drop in temperature.
Chemical Equation
The balanced chemical equation representing this reaction is:
Ba(OH)₂(aq) + 2NH₄Cl(aq) → BaCl₂(aq) + 2NH₃(g) + 2H₂O(l)
Products of the Reaction
The reaction yields three distinct products:
- Barium Chloride (BaCl₂): This is an ionic salt that typically remains in solution (aqueous) if the reaction occurs in water.
- Ammonia (NH₃): This is a pungent gas that is evolved during the reaction, often detectable by its characteristic smell.
- Water (H₂O): Water is also formed as a product of the reaction.
Key Characteristics of the Reaction
This reaction exhibits several important characteristics:
- Type of Reaction: It is a double displacement reaction, where the ions of two compounds swap places. In this case, barium exchanges with ammonium, and hydroxide exchanges with chloride.
- Gas Evolution: The production of ammonia gas (NH₃) makes it a gas evolution reaction.
- Endothermic Nature: One of the most notable features is its endothermicity. When this reaction occurs, it absorbs heat, causing the surrounding temperature to decrease. This property is sometimes used in educational demonstrations to show a cooling effect.
Summary Table
To summarize the key aspects of the reaction:
Feature | Description |
---|---|
Reactants | Barium Hydroxide (Ba(OH)₂) |
Ammonium Chloride (NH₄Cl) | |
Products | Barium Chloride (BaCl₂) |
Ammonia (NH₃) | |
Water (H₂O) | |
Reaction Type | Double Displacement, Gas Evolution |
Energy Change | Endothermic (absorbs heat) |
Practical Insights
- Demonstrations: Due to its endothermic nature and gas evolution, this reaction is often used in chemistry demonstrations to illustrate heat absorption and the production of a gas with a distinct odor.
- Safety: Ammonia gas is an irritant, and barium compounds are toxic. This reaction should be performed with proper ventilation and safety precautions.