Chemical Changes Quiz

What is a phase change?

• A change in state or form in which no new substance forms.

• A process where a substance burns.

• A reaction that produces light.

• A method of mixing chemicals.

Which of the following is an example of a chemical change?

• Burning wood to produce ash and smoke.

• Melting ice to form water.

• Dissolving sugar in water.

• Evaporating water from a solution.

Which observation does NOT typically indicate a chemical reaction?

• Change in temperature

• Change in shape

• Gas evolution (effervescence)

• Formation of a new solid (precipitate)

Why is it important to wear goggles during laboratory procedures?

• To protect your eyes from potential chemical splashes.

• To look stylish in the lab.

• To help you see better in the dark.

• To avoid smelling chemicals.

What should you do if you are unsure whether a chemical is safe?

• Always treat all chemicals as if they are dangerous.

• Assume it is safe if it looks harmless.

• Ask a friend for advice.

• Ignore safety instructions.

What is the maximum amount of time you should spend on any one step in the procedure?

• Five minutes

• Ten minutes

• Three minutes

• One minute

What should you do at the conclusion of each procedure?

• Leave the solutions in the test tubes

• Pour all solutions into a waste container

• Rinse all solutions down the drain

• Store the solutions for later use

In Station 1, what is added to the dilute hydrochloric acid in the test tube?

• Sodium sulfate

• Magnesium metal

• Calcium chloride

• Potassium thiocyanate

Which two solutions are mixed together in Station 2?

• Hydrochloric acid and magnesium metal

• Iron(III) nitrate and potassium thiocyanate

• Sodium sulfate and calcium chloride

• Sodium sulfate and potassium thiocyanate

What is the purpose of recording observations in detail, such as writing “turned from blue to red” instead of just “turned red”?

• To make the report longer

• To be more complete and specific in observations

• To use more scientific words

• To impress the teacher