Why should a final conclusion about a chemical reaction not be drawn from colour change alone?
Answer and explanation
Correct answer: Because colour change may also result from physical changes such as mixing or dilution and does not confirm the formation of a new substance.
A colour change may indicate a chemical reaction, but by itself it does not prove that a new substance has formed. A change in colour can also be observed during physical processes such as mixing or dilution. Therefore, additional evidence, such as gas evolution, precipitate formation, temperature change, or a suitable test for a new substance, is needed. Option B is incorrect because many chemical reactions do not evolve a gas.
Frequently asked questions
What is the correct answer to this question?
Because colour change may also result from physical changes such as mixing or dilution and does not confirm the formation of a new substance.
Why is this the correct answer?
A colour change may indicate a chemical reaction, but by itself it does not prove that a new substance has formed. A change in colour can also be observed during physical processes such as mixing or dilution. Therefore, additional evidence, such as gas evolution, precipitate formation, temperature change, or a suitable test for a new substance, is needed. Option B is incorrect because many chemical reactions do not evolve a gas.
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.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
