Why is it not correct to depend on only one sign while identifying a reaction?
Answer and explanation
Correct answer: Because different reactions can show different signs
The governing idea is that chemical reactions may be identified through observable evidence, but no single sign is universal. A reaction may produce a colour change, gas, precipitate, temperature change, or smell, and another reaction may show a different combination. Therefore option A is correct: several relevant observations should be considered before concluding that a reaction has occurred. The other choices incorrectly reject all evidence or overvalue colour alone.
Frequently asked questions
What is the correct answer to this question?
Because different reactions can show different signs
Why is this the correct answer?
The governing idea is that chemical reactions may be identified through observable evidence, but no single sign is universal. A reaction may produce a colour change, gas, precipitate, temperature change, or smell, and another reaction may show a different combination. Therefore option A is correct: several relevant observations should be considered before concluding that a reaction has occurred. The other choices incorrectly reject all evidence or overvalue colour alone.
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.
