In an unknown process, a substance with new properties was formed, and the total mass in a closed container was the same before and after the process. What is the most appropriate conclusion?
Answer and explanation
Correct answer: A chemical reaction occurred, and the law of conservation of mass applied.
The formation of a substance with new properties shows that a new substance was produced; therefore, the process is a chemical reaction. The equality of total mass before and after the reaction in a closed container is consistent with the law of conservation of mass. Options A and D describe physical changes, which do not produce a new substance, while option B contradicts the observation.
Frequently asked questions
What is the correct answer to this question?
A chemical reaction occurred, and the law of conservation of mass applied.
Why is this the correct answer?
The formation of a substance with new properties shows that a new substance was produced; therefore, the process is a chemical reaction. The equality of total mass before and after the reaction in a closed container is consistent with the law of conservation of mass. Options A and D describe physical changes, which do not produce a new substance, while option B contradicts the observation.
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.
