Which of the following could provide definite evidence of a chemical reaction choose two correct answers
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.
There are several pieces of evidence that can indicate a chemical reaction has occurred. Two such pieces of evidence include:
1. Production of a gas: If bubbles or a gas is formed during a reaction, it suggests a chemical change. For example, when baking soda reacts with vinegar, carbon dioxide gas is produced, resulting in the formation of bubbles.
2. Formation of a precipitate: A precipitate is a solid substance that forms from a chemical reaction in a liquid solution. If a reaction results in the formation of a solid, it indicates a chemical change. An example is when silver nitrate reacts with sodium chloride, forming a white precipitate of silver chloride.