Question

1. which of the following is/are true? a mixing an acid with base to produce salt and water is a physical change b inflating a volleyball is a chemical change c tarnishing of silver is a chemical change d all of the above

Explanation:

• a: Mixing an acid and a base is a chemical reaction (neutralization), not a physical change. A new substance (salt and water) is formed.
• b: Inflating a volleyball is a physical change as it only changes the volume and shape of the ball, no new substances are formed.
• c: Tarnishing of silver occurs when silver reacts with sulfur - containing compounds in the air to form silver sulfide, a new substance. So it is a chemical change.

Answer:

C. Tarnishing of silver is a chemical change