In an unknown process, a new substance was formed, the colour changed, and the total mass remained the same in a closed container. What is the most appropriate conclusion?
Answer and explanation
Correct answer: A chemical reaction occurred, and the law of conservation of mass was obeyed.
Formation of a new substance is a key indicator of a chemical reaction. The equality of total mass of reactants and products in a closed container demonstrates the law of conservation of mass. Colour change alone can sometimes occur in a physical change, but the formation of a new substance here confirms a chemical change.
Frequently asked questions
What is the correct answer to this question?
A chemical reaction occurred, and the law of conservation of mass was obeyed.
Why is this the correct answer?
Formation of a new substance is a key indicator of a chemical reaction. The equality of total mass of reactants and products in a closed container demonstrates the law of conservation of mass. Colour change alone can sometimes occur in a physical change, but the formation of a new substance here confirms a chemical change.
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.
