If gas evolves in an unknown reaction but colour does not change what will be the most careful conclusion?
Answer and explanation
Correct answer: Gas formation may be a sign of chemical reaction
A careful scientific conclusion must rely on evidence without claiming more than the observation proves. Evolution of a gas may indicate that a new substance has formed, so it can be evidence of a chemical reaction. However, absence of colour change does not rule out a reaction, because many reactions show no visible colour change. The observation alone cannot prove that the change is physical or specifically rusting; therefore option A is best.
Frequently asked questions
What is the correct answer to this question?
Gas formation may be a sign of chemical reaction
Why is this the correct answer?
A careful scientific conclusion must rely on evidence without claiming more than the observation proves. Evolution of a gas may indicate that a new substance has formed, so it can be evidence of a chemical reaction. However, absence of colour change does not rule out a reaction, because many reactions show no visible colour change. The observation alone cannot prove that the change is physical or specifically rusting; therefore option A is best.
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.
