Calcium Reacting with Water
Ca + 2H2O → Ca(OH)2 + H2
Overview
Calcium reacts with water to produce calcium hydroxide (limewater) and hydrogen gas. The reaction is moderately vigorous, producing a milky suspension of sparingly soluble calcium hydroxide. Calcium sinks in water (unlike sodium) and reacts at the bottom of the vessel.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Calcium Ca | 1 | (s) |
| Reactant | Water H₂O | 2 | (l) |
| Product | Calcium Hydroxide Ca(OH)₂ | 1 | (s) |
| Product | Hydrogen H | 1 | (g) |
Everyday Example
The milky appearance of hard water deposits and limescale is related to calcium hydroxide and carbonate formation from calcium's reactions in water.
Industrial Importance
Understanding calcium-water reactions is important for water hardness treatment, concrete chemistry, and calcium hydroxide production for industrial applications.
Properties
- Type
- Single Replacement
- Reversible
- No
- Energy
- Exothermic
- ΔH
- -635.1 kJ/mol
Related Reactions
Aluminum Reacting with Hydrochloric Acid
Aluminum Reacting with Iron(III) Oxide (Thermite)
Aluminum Reducing Chromium Oxide (Aluminothermic)
Carbon Reducing Iron Oxide in Blast Furnace
Chlorine Displacing Bromine from Sodium Bromide
Chlorine Displacing Iodine from Potassium Iodide
Copper Displacing Silver from Silver Nitrate
Fluorine Displacing Chlorine from Sodium Chloride
Hydrogen Reducing Copper Oxide
Iron Displacing Copper from Copper Sulfate
Frequently Asked Questions
What is the equation for Calcium Reacting with Water?
The balanced equation is: Ca + 2H₂O → Ca(OH)₂ + H₂.
What type of reaction is Calcium Reacting with Water?
Calcium Reacting with Water is a single replacement reaction.
Is Calcium Reacting with Water exothermic or endothermic?
Calcium Reacting with Water is exothermic (releases energy). The enthalpy change (ΔH) is -635.1 kJ/mol.