Physical and Chemical Changes Quiz

Study the given diagram carefully and choose the correct answer. A student conducted an experiment and a balloon placed on the bottle inflates. Which conclusion is most accurate?

1. The vinegar evaporated into the balloon
2. A chemical change occurred forming a new gas
3. The gas was already inside the vinegar
4. This is a physical change involving bubbles

Answer: (b) A chemical change occurred forming a new gas

Lesley accidentally spilled tea on a white cotton tablecloth. Her mother first dried it under the sun, then tried to scrub it using soap, and finally used a lemon slice to remove the stain. Which of the following steps involved a chemical change?

1. Drying under the sun
2. Scrubbing with soap
3. Applying lemon juice
4. Washing the cloth in water

Answer: (c) Applying lemon juice

Match the transformation in Column A with the correct classification in Column B. Column A Column B P Cutting wood into pieces 1 Physical change Q Burning of wood 2 Irreversible change R Melting of candle wax 3 Both physical & chemical change S Lighting a candle 4 Chemical change

1. P–2, Q–4, R–1, S–3
2. P–1, Q–2, R–4, S–3
3. P–4, Q–1, R–2, S–3
4. P–2, Q–4, R–3, S–1

Answer: (a) P–2, Q–4, R–1, S–3

Which process among the ones shown or suggested in the diagram involves a chemical change?

Answer: (d)

Based on the scene shown, Identify the correct set of physical and chemical changes from the options below:

1. A
2. B
3. C
4. D

Answer: (a) A

Three reaction types are described: Set A: Produces heat Set B: Produces gas Set C : Results in a solid product A reaction lies in the region X. Which one best fits from the options given?

1. Burning of wood
2. Reaction of vinegar and baking soda
3. Mixing barium chloride with sodium sulfate
4. Melting of ice

Answer: (b) Reaction of vinegar and baking soda

Choose the correct statement about the metal fence shown in the given picture during monsoon.

1. It is a reversible change that can be stopped by reaction with water and air.
2. It is a physical change because the shape of the fence remains the same.
3. It is a chemical change and an example of a combination reaction.
4. It is an endothermic change because heat is absorbed during the process.

Answer: (c) It is a chemical change and an example of a combination reaction.

Observe the circuit diagram given. When the switch is turned ON, current flows through the circuit. Which of the following correctly describes the chemical reaction that takes place in the solution when the switch is turned ON?

1. Silver gets displaced by copper from the solution.
2. Copper and silver combine to form a new compound.
3. A white insoluble substance settles at the bottom.
4. Silver nitrate breaks into silver and nitrogen gas.

Answer: (a) Silver gets displaced by copper from the solution.

The graph shows the change in temperature over time for four different reactions (W, X, Y, Z). Based on the nature of temperature change, identify which reaction curve most likely represents the combination reaction.

1. W
2. X
3. Y
4. Z

Answer: (a) W

Choose the incorrect set of statements. 1. Neutralisation between an acid and a base is a chemical change. 2. Decomposition of hydrogen peroxide is a fast chemical change producing oxygen gas. 3. Precipitation reactions produce insoluble solids during chemical change. 4. Fermentation of sugar is a slow chemical change.

1. 1 and 2
2. 2 and 4
3. 1 and 3
4. 2 only

Answer: (d) 2 only