Which of the following best explains how fizzing (gas evolution) occurs during a chemical reaction?

• A. Fizzing occurs when solid particles dissolve completely in a liquid.
• B. A gas is produced as a product when reactants undergo a chemical change, escaping as bubbles.
• C. Fizzing is caused by the evaporation of the liquid reactant.
• D. The reactants absorb gas from the air, causing bubbles to form.

Answer: (B)

Verified step by step guidance

1. Understand that fizzing or gas evolution during a chemical reaction is a physical observation indicating the formation of a gas.
2. Recognize that gas bubbles form when a gas is produced as a product of a chemical reaction, which then escapes from the liquid as bubbles.
3. Eliminate options that describe physical processes unrelated to gas production, such as solid particles dissolving or evaporation of the liquid.
4. Note that absorption of gas from the air by reactants does not typically cause fizzing; fizzing is due to gas generated within the reaction itself.
5. Conclude that the best explanation is that fizzing occurs because a gas is produced as a product when reactants undergo a chemical change, escaping as bubbles.