When water is added to calcium oxide, calcium hydroxide is formed and heat is released. What type of reaction is this?
Answer and explanation
Correct answer: Exothermic combination
The reaction is \(\mathrm{CaO + H_2O \rightarrow Ca(OH)_2 + heat}\). Two reactants combine to form one product, calcium hydroxide, so it is a combination reaction. Since heat is released, it is also exothermic. In a decomposition reaction, one compound breaks down into simpler substances, which does not occur here.
Frequently asked questions
What is the correct answer to this question?
Exothermic combination
Why is this the correct answer?
The reaction is \(\mathrm{CaO + H_2O \rightarrow Ca(OH)_2 + heat}\). Two reactants combine to form one product, calcium hydroxide, so it is a combination reaction. Since heat is released, it is also exothermic. In a decomposition reaction, one compound breaks down into simpler substances, which does not occur here.
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.
