Magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen gas.
Here's a more detailed explanation of the reaction:
Magnesium (Mg) is a reactive metal that readily donates electrons. Hydrochloric acid (HCl) is a strong acid that provides hydrogen ions (H⁺) in solution. When magnesium is added to hydrochloric acid, a redox reaction occurs.
- Magnesium is oxidized: Magnesium atoms lose two electrons each (Mg → Mg²⁺ + 2e⁻), becoming magnesium ions (Mg²⁺).
- Hydrogen ions are reduced: Hydrogen ions from the hydrochloric acid gain electrons (2H⁺ + 2e⁻ → H₂) to form hydrogen gas (H₂).
- Magnesium chloride is formed: The magnesium ions (Mg²⁺) combine with chloride ions (Cl⁻) from the hydrochloric acid to form magnesium chloride (MgCl₂), which dissolves in the water.
Chemical Equation:
The unbalanced chemical equation for this reaction is:
Mg (s) + HCl (aq) → MgCl₂ (aq) + H₂ (g)
The balanced chemical equation is:
Mg (s) + 2HCl (aq) → MgCl₂ (aq) + H₂ (g)
Observations:
Several observable changes indicate that a chemical reaction is taking place:
- Effervescence (Bubbling): The production of hydrogen gas causes bubbling.
- Dissolution of Magnesium: The magnesium metal gradually disappears as it reacts.
- Heat Generation: The reaction is exothermic, meaning it releases heat, and the solution will become warmer.
- Formation of a Clear Solution: If excess magnesium isn't used, the final solution will be clear and colorless as magnesium chloride is soluble in water.
Safety Precautions:
- Hydrogen gas is flammable and should be handled with caution. Avoid open flames or sparks near the reaction.
- Hydrochloric acid is corrosive. Wear appropriate personal protective equipment, such as gloves and safety goggles, to prevent skin and eye contact.
- Perform the reaction in a well-ventilated area to prevent the build-up of hydrogen gas.
