Sodium reacts vigorously with water to produce sodium hydroxide and hydrogen gas, releasing a significant amount of heat in an exothermic reaction.
The Reaction Explained
When sodium (Na) is added to water (H₂O), a chemical reaction occurs, producing sodium hydroxide (NaOH) and hydrogen gas (H₂). The balanced chemical equation for this reaction is:
2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)
Here's a breakdown of what happens:
- Sodium's Activity: Sodium is a highly reactive alkali metal. It readily loses its single valence electron.
- Electron Transfer: Sodium donates an electron to a water molecule.
- Formation of Hydroxide: This leads to the formation of hydroxide ions (OH⁻) and hydrogen gas (H₂). The hydroxide ions dissolve in the water, forming sodium hydroxide (NaOH), a strong base.
- Exothermic Nature: The reaction is highly exothermic, meaning it releases a large amount of heat. This heat can ignite the hydrogen gas produced, resulting in a flame or even a small explosion.
Observations
You can observe the following when sodium reacts with water:
- Fizzing/Bubbling: This is due to the evolution of hydrogen gas.
- Heat Production: The water will become warm, and steam may be produced.
- Flame: If the reaction is vigorous enough, the hydrogen gas will ignite, producing a yellow flame (characteristic of sodium).
- Movement: The sodium metal will melt into a small ball and dart around on the water's surface due to the escaping hydrogen.
- Formation of a Base: The resulting solution will be alkaline (basic) due to the presence of sodium hydroxide.
Safety Precautions
Due to the vigorous and exothermic nature of the reaction, it is crucial to handle sodium with care. Always wear appropriate safety gear, including gloves and eye protection, and perform the reaction in a well-ventilated area. Only use small pieces of sodium at a time.
