International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What does the word equation for ammonium chloride formation look like?

1. Ammonia + Hydrogen chloride → Ammonium chloride

2. Ammonia + Hydrogen → Ammonium chloride

3. Hydrogen chloride + Chlorine → Ammonium chloride

4. Ammonia + Water → Ammonium chloride

The correct answer is: Ammonia + Hydrogen chloride → Ammonium chloride

The word equation for the formation of ammonium chloride is accurately represented by ammonia and hydrogen chloride reacting to produce ammonium chloride. This is a straightforward acid-base reaction where ammonia (NH₃) acts as a base and hydrogen chloride (HCl) serves as an acid. When they combine, they form the salt ammonium chloride (NH₄Cl). In this process, ammonia accepts a proton (H⁺) from hydrogen chloride, leading to the formation of the ammonium ion (NH₄⁺), which then pairs with the chloride ion (Cl⁻) to create the ionic compound ammonium chloride. Understanding this reaction illustrates the fundamental principles of acid-base chemistry, showcasing how gases can react to form a solid compound. The other choices involve incorrect reactants or product combinations that do not accurately reflect the chemical reaction involved in producing ammonium chloride.