When sodium silicate reacts with calcium chloride, they combine to produce calcium silicate, which is characterized as a flaky white solid. This reaction typically occurs when both substances are dissolved in water.
The interaction between sodium silicate and calcium chloride is a classic example of a double displacement (or metathesis) reaction, which results in the formation of an insoluble precipitate.
What Happens
- Reactants: The process begins with sodium silicate (Na₂SiO₃), often known as "water glass," and calcium chloride (CaCl₂). Both are typically in aqueous (dissolved in water) solutions.
- Process: As stated, the calcium chloride and sodium silicate react in water. When these solutions are mixed, the calcium ions (Ca²⁺) from calcium chloride and the silicate ions (SiO₃²⁻) from sodium silicate combine.
- Product: The primary product formed is calcium silicate (CaSiO₃). This compound is largely insoluble in water, leading to its precipitation out of the solution.
- Appearance: The calcium silicate formed is a flaky white solid, making the reaction easily observable.
- Byproduct: Sodium chloride (NaCl) is also formed as a soluble byproduct, remaining dissolved in the water.
Chemical Equation
The balanced chemical equation for this reaction is:
Na₂SiO₃(aq) + CaCl₂(aq) → CaSiO₃(s) + 2NaCl(aq)
Where:
- (aq) denotes an aqueous solution (dissolved in water)
- (s) denotes a solid precipitate
Key Characteristics of the Reaction
- Precipitation Reaction: The formation of the insoluble calcium silicate solid makes this a precipitation reaction.
- Visible Change: The appearance of the flaky white solid provides a clear visual indicator that a chemical reaction has taken place.
- Industrial Relevance: Calcium silicate is a versatile material used in various applications, including as a component in cement, insulation materials, and as an additive in certain manufacturing processes.
Summary of Reactants and Products
To better illustrate the transformation, here's a quick overview:
| Component | Chemical Formula | State in Reaction | Role | Key Characteristic |
|---|---|---|---|---|
| Sodium Silicate | Na₂SiO₃ | Aqueous | Reactant | Source of silicate ions |
| Calcium Chloride | CaCl₂ | Aqueous | Reactant | Source of calcium ions |
| Calcium Silicate | CaSiO₃ | Solid | Main Product | Flaky white precipitate, insoluble in water |
| Sodium Chloride | NaCl | Aqueous | Byproduct | Remains dissolved in solution, common table salt |
This reaction is a straightforward demonstration of how soluble ionic compounds can exchange ions to form new, insoluble compounds when mixed in a solution.
