Question

Name the type of chemical reaction in which calcium oxide reacts with water. Justify your answer by giving balanced chemical equation for the chemical reaction.

Answer 1

Step 1: Identifying the Type of Reaction:
The reaction between calcium oxide (CaO) and water (H₂O) is a type of combination reaction. In a combination reaction, two or more reactants combine to form a single product. Here, calcium oxide and water combine to form calcium hydroxide. Therefore, it is classified as a combination reaction.

Step 2: Understanding the Reactants:
- Calcium Oxide (CaO): It is a basic oxide that is produced by heating calcium carbonate (limestone). Calcium oxide is also known as quicklime.
- Water (H₂O): Water is a common liquid reactant in various chemical reactions, and here, it will react with calcium oxide.

Step 3: Reaction Process:
When calcium oxide (CaO) is added to water (H₂O), it reacts to form calcium hydroxide (Ca(OH)₂). The reaction is exothermic, meaning it releases heat.

Step 4: Writing the Unbalanced Chemical Equation:
The unbalanced equation for the reaction is: \[ \text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 \] This equation shows that calcium oxide reacts with water to form calcium hydroxide.

Step 5: Balancing the Chemical Equation:
To balance the chemical equation, check the number of atoms of each element on both sides of the equation:
- On the left side, we have 1 calcium (Ca), 1 oxygen (O), and 2 hydrogen (H) atoms.
- On the right side, we have 1 calcium (Ca), 2 oxygen (O), and 2 hydrogen (H) atoms.
Both sides of the equation have the same number of atoms for each element, so the equation is already balanced.

Step 6: Final Balanced Chemical Equation:
The final balanced chemical equation for the reaction between calcium oxide and water is: \[ \text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 \] This equation shows that calcium oxide reacts with water to form calcium hydroxide.

Step 7: Conclusion:
This reaction is an example of a combination reaction, where two reactants (calcium oxide and water) combine to form a single product (calcium hydroxide). The reaction is also exothermic, meaning it releases heat during the process.