If the reaction mixture is not heated externally, which observation strongly suggests an exothermic reaction?
Answer and explanation
Correct answer: The temperature of the reaction mixture and container rises
In an exothermic reaction, heat is released from the reaction mixture to the surroundings. Therefore, when no external heat is supplied, a rise in the temperature of the mixture and container strongly indicates heat release. Option B may indicate an endothermic reaction, whereas gas evolution or a colour change may show that a reaction is occurring but do not by themselves identify the direction of heat flow.
Frequently asked questions
What is the correct answer to this question?
The temperature of the reaction mixture and container rises
Why is this the correct answer?
In an exothermic reaction, heat is released from the reaction mixture to the surroundings. Therefore, when no external heat is supplied, a rise in the temperature of the mixture and container strongly indicates heat release. Option B may indicate an endothermic reaction, whereas gas evolution or a colour change may show that a reaction is occurring but do not by themselves identify the direction of heat flow.
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.
