When sulphuric acid reacts with calcium oxide, the exact products formed are calcium sulfate and water. This is a classic example of a neutralization reaction between a basic oxide and an acid.
Understanding the Reaction
Calcium oxide (CaO), commonly known as quicklime, is a basic oxide. Sulphuric acid (H₂SO₄) is a strong mineral acid. When these two substances react, they undergo a neutralization process, which typically yields a salt and water.
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Reactants:
- Calcium Oxide (CaO)
- Sulphuric Acid (H₂SO₄)
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Products:
- Calcium Sulfate (CaSO₄)
- Water (H₂O)
The reference confirms this, stating that the reaction of dilute sulphuric acid with calcium oxide "will result in the formation of a sparingly soluble salt, calcium sulphate and of course, water."
Key Products Explained
1. Calcium Sulfate (CaSO₄)
Calcium sulfate is the salt formed from this neutralization reaction. As highlighted in the provided reference, it is a sparingly soluble salt. This means that while some of it will dissolve in water, a significant portion will remain as a solid precipitate, which might be observed as a white solid or suspension. Common forms of calcium sulfate include gypsum (dihydrate) and anhydrite (anhydrous).
2. Water (H₂O)
Water is the other product of this acid-base neutralization. It is formed from the combination of hydrogen ions (H⁺) from the acid and oxide ions (O²⁻) from the calcium oxide, or more generally, hydroxide ions (OH⁻) if calcium oxide first reacts with water to form calcium hydroxide.
Chemical Equation
The direct reaction between calcium oxide and sulphuric acid can be represented by the following balanced chemical equation:
CaO(s) + H₂SO₄(aq) → CaSO₄(s) + H₂O(l)
Where:
sdenotes solidaqdenotes aqueous solutionldenotes liquid
Related Observations from the Reference
The reference also provides an example of a similar neutralization reaction involving a calcium base: Ca(OH)₂(aq) + H₂SO₄(aq) → CaSO₄(s) + 2H₂O(l). While this specific equation uses calcium hydroxide (slaked lime) instead of calcium oxide, it illustrates the general principle of neutralization forming calcium sulfate and water. In practical applications, calcium oxide can react with water to form calcium hydroxide, which then reacts further with the acid. However, the direct reaction with calcium oxide still yields the same primary products.
Summary of Reaction
To summarize the reaction between sulphuric acid and calcium oxide:
| Aspect | Description |
|---|---|
| Reactants | Calcium Oxide (CaO) and Sulphuric Acid (H₂SO₄) |
| Reaction Type | Neutralization (Acid-Base Reaction) |
| Primary Products | Calcium Sulfate (CaSO₄) and Water (H₂O) |
| Solubility of Salt | Calcium Sulfate is a sparingly soluble salt, as per the reference. |
| Observations | A typical neutralization reaction, potentially forming a white precipitate. |
