In which condition can conservation of mass be checked most correctly?
Answer and explanation
Correct answer: Comparing total mass after carrying out reaction in a closed container
The law of conservation of mass states that total mass remains constant in a chemical reaction when matter is not allowed to enter or leave the system. A closed container retains reactants and any gaseous products, so measuring and comparing the total mass before and after the reaction provides the best test. Therefore A is correct; colour and smell are qualitative observations, not mass measurements.
Frequently asked questions
What is the correct answer to this question?
Comparing total mass after carrying out reaction in a closed container
Why is this the correct answer?
The law of conservation of mass states that total mass remains constant in a chemical reaction when matter is not allowed to enter or leave the system. A closed container retains reactants and any gaseous products, so measuring and comparing the total mass before and after the reaction provides the best test. Therefore A is correct; colour and smell are qualitative observations, not mass measurements.
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.
