Displacement of Hydrogen from Acid by Magnesium

Mg + 2HCl → MgCl2 + H2

Overview

Magnesium is oxidized from Mg⁰ to Mg²⁺ while hydrogen ions are reduced from H⁺ to H₂. This vigorous redox reaction produces rapid hydrogen evolution and significant heat. The reaction rate can be studied by varying acid concentration, temperature, or magnesium surface area.

Participants

Role Substance Coefficient State
Reactant Magnesium Mg 1 (s)
Reactant Hydrochloric Acid HCl 2 (aq)
Product Hydrogen H 1 (g)

Everyday Example

This reaction is commonly used in school chemistry labs to study reaction kinetics by measuring the rate of hydrogen gas evolution.

Industrial Importance

Understanding metal-acid redox reactions is fundamental to corrosion science, electrochemistry, and metallurgical processing.

Properties

Type
Redox
Reversible
No
Energy
Exothermic
ΔH
-462.0 kJ/mol

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Frequently Asked Questions

What is the equation for Displacement of Hydrogen from Acid by Magnesium?
The balanced equation is: Mg + 2HCl → MgCl₂ + H₂.
What type of reaction is Displacement of Hydrogen from Acid by Magnesium?
Displacement of Hydrogen from Acid by Magnesium is a redox reaction.
Is Displacement of Hydrogen from Acid by Magnesium exothermic or endothermic?
Displacement of Hydrogen from Acid by Magnesium is exothermic (releases energy). The enthalpy change (ΔH) is -462.0 kJ/mol.