Question

Question 9

Which of the following statement is incorrect for a chemical reaction?
(a) Heat may be given out but never absorbed.
(b) Sound may be produced.
(c) A colour change may take place.
(d) A gas may be evolved.

Answer 1

The explanation for the correct option:

Option(a)Heat may be given out but never absorbed.

• ​During a chemical reaction, the heat may be released or absorbed.
• The reaction in which heat is released during the process is called an exothermic reaction.
• The reaction in which heat is absorbed during the process is called an endothermic reaction.
• So Heat may be given out as well as absorbed during chemical reactions.

The explanation for the incorrect option:

(b) Sound may be produced.
(c) A color change may take place.
(d) A gas may be evolved.
These all are indications of a chemical reaction. when these things happen we can confirm that there is a chemical change takes place. Hence, these all are related to a chemical reaction.

Hence option (a))Heat may be given out but never absorbed. is the incorrect statement.