When water is added to calcium oxide, the container becomes hot. What does this indicate?
Answer and explanation
Correct answer: Heat was released
Calcium oxide reacts with water to form calcium hydroxide: \(\mathrm{CaO + H_2O \rightarrow Ca(OH)_2}\). Heat is released during this reaction, so the container becomes hot. Therefore, it is an exothermic reaction. In contrast, if heat were absorbed as in option A, the container would tend to become cooler.
Frequently asked questions
What is the correct answer to this question?
Heat was released
Why is this the correct answer?
Calcium oxide reacts with water to form calcium hydroxide: \(\mathrm{CaO + H_2O \rightarrow Ca(OH)_2}\). Heat is released during this reaction, so the container becomes hot. Therefore, it is an exothermic reaction. In contrast, if heat were absorbed as in option A, the container would tend to become cooler.
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.
