What are the product and energy change when water is added to calcium oxide?
Answer and explanation
Correct answer: Calcium hydroxide and heat release
When quicklime reacts with water, the equation is CaO + H₂O → Ca(OH)₂ + heat. The product is calcium hydroxide, commonly called slaked lime. Because heat is released rather than absorbed, the process is exothermic. Calcium carbonate would require carbon dioxide, while calcium chloride and calcium sulphate require different reactants, so those options do not fit this reaction.
Frequently asked questions
What is the correct answer to this question?
Calcium hydroxide and heat release
Why is this the correct answer?
When quicklime reacts with water, the equation is CaO + H₂O → Ca(OH)₂ + heat. The product is calcium hydroxide, commonly called slaked lime. Because heat is released rather than absorbed, the process is exothermic. Calcium carbonate would require carbon dioxide, while calcium chloride and calcium sulphate require different reactants, so those options do not fit this reaction.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
