When water is added to calcium oxide, one product forms and heat is released. What is the correct combined identification?
Answer and explanation
Correct answer: Combination and exothermic
Calcium oxide reacts with water as CaO + H₂O → Ca(OH)₂. Two reactants combine to produce a single product, calcium hydroxide, so the reaction is a combination reaction. Because heat is released to the surroundings, it is also exothermic. Therefore, option A correctly identifies both features; the other options describe different reaction types or energy changes.
Frequently asked questions
What is the correct answer to this question?
Combination and exothermic
Why is this the correct answer?
Calcium oxide reacts with water as CaO + H₂O → Ca(OH)₂. Two reactants combine to produce a single product, calcium hydroxide, so the reaction is a combination reaction. Because heat is released to the surroundings, it is also exothermic. Therefore, option A correctly identifies both features; the other options describe different reaction types or energy changes.
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.
