When dilute hydrochloric acid reacts with sodium sulphite, a chemical reaction occurs that produces several substances, including a gas with a distinct smell.
The Reaction Explained
The interaction between dilute hydrochloric acid (HCl) and sodium sulphite (Na₂SO₃) is a classic acid-base reaction involving a sulphite salt. Acids react with sulphites to liberate sulphur dioxide gas.
Based on the provided information: "Therefore, the reaction between dil. and Sodium sulphite ( Na₂SO₃ ) produces Sulphur dioxide gas( ), Sodium chloride and water."
This means the reactants, dilute hydrochloric acid and sodium sulphite, are transformed into specific products.
Products of the Reaction
The reaction yields three main products:
- Sulphur dioxide gas (SO₂): This is a colourless gas with a pungent, choking smell. Its formation is a key indicator that the reaction is taking place.
- Sodium chloride (NaCl): This is a salt, commonly known as table salt, which remains dissolved in the solution.
- Water (H₂O): This is also produced and mixes with the aqueous solution.
Chemical Equation
The balanced chemical equation representing this reaction is:
Na₂SO₃(aq) + 2HCl(aq) → 2NaCl(aq) + H₂O(l) + SO₂(g)
This equation shows that one molecule of sodium sulphite reacts with two molecules of hydrochloric acid to produce two molecules of sodium chloride, one molecule of water, and one molecule of sulphur dioxide gas.
Summary of Reactants and Products
Here is a simple breakdown:
| Reactant 1 | Reactant 2 | Product 1 | Product 2 | Product 3 |
|---|---|---|---|---|
| Dilute Hydrochloric Acid | Sodium Sulphite (Na₂SO₃) | Sodium Chloride (NaCl) | Water (H₂O) | Sulphur Dioxide (SO₂) |
Key Observations
When performing this reaction, you would typically observe:
- Bubbling (effervescence) due to the release of sulphur dioxide gas.
- A noticeable, pungent smell characteristic of sulphur dioxide.
- The solid sodium sulphite dissolving as it reacts with the acid.
This reaction is often used in laboratories to generate small quantities of sulphur dioxide gas for experiments or demonstrations.
