Cobalt Chloride Color Change Experiment

The video tutorial demonstrates an experiment using cobalt chloride, a less common chemical in labs. The experiment involves writing with cobalt chloride solution and observing color changes when heat is applied. The color shifts from pink to blue due to equilibrium changes and reverts to pink upon cooling. This engaging experiment is suitable for classroom settings, allowing students to participate and take their work home.

What is the chemical used in the experiment that is not commonly found in everyday labs?

• Sodium chloride

• Calcium carbonate

• Cobalt chloride

• Potassium permanganate

What is the first step in the experiment involving cobalt chloride?

• Freezing the solution

• Dissolving it in water

• Heating the solution

• Mixing with oil

How long does it take for the writing to dry before the experiment can proceed?

• 15 to 20 minutes

• 10 minutes

• 30 minutes

• 5 minutes

What happens to the color of cobalt chloride when heat is applied?

• It turns blue

• It turns green

• It turns yellow

• It turns red

What causes the color change in the cobalt chloride experiment?

• A chemical reaction

• A shift in equilibrium

• A change in pH

• A change in pressure

What color does the cobalt chloride return to when cooled?

• Blue

• Yellow

• Green

• Pink

What is the visual effect observed when the paper is heated and then cooled?

• The color changes from pink to blue and back to pink

• The paper shrinks

• The paper changes texture

• The paper becomes transparent

What is a suggested way to engage students in the experiment?

• Ask them to heat the paper

• Invite them to write their names with the solution

• Have them mix the chemicals

• Let them observe from a distance

What can students do with the paper after the experiment?

• Throw it away

• Take it home and repeat the experiment

• Use it as a bookmark

• Recycle it

How long does the color change effect last?

• A few seconds

• A few minutes

• A few hours

• A quite long time