Which of the following could provide definite evidence of a chemical reaction choose two correct answers

1 answer

The correct answers could be:

1) Formation of a precipitate: When two substances react and form a solid precipitate, it provides definite evidence of a chemical reaction. This happens when two soluble substances are mixed, and an insoluble compound is formed.

2) Evolution of gas: If a gas is produced during the reaction, such as the formation of bubbles or fizzing, it is a clear indication of a chemical reaction. This release of gas is usually due to the formation of a new substance with different properties than the reactants.