Chemical and Physical Changes Quiz

An experiment was done where a crystal substance was added to a beaker of liquid that was room temperature. The following observations were made during the experiment. 1. The crystals dissolved 2. A precipitate formed 3. The bottom of the beaker felt warm to the touch 4. Bubbles formed in the water. All of the observations are evidence that a chemical change occurred EXCEPT—

• observation I.

• observation II.

• observation III.

• observation IV.

Physical changes affect the—

• color of an object.

• chemical structure of an object.

• Flammability of an object

• observable properties of an object.

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

• Mixing two substances and seeing bubbles

• Dissolving powder into water

• Coloring on paper to produce a color change

• Cutting wood to change the shape

Which of the following is a sign that a chemical reaction (or change) has occurred?

• change in shape

• melting

• formation of a gas

• dissolving

A chemical change is different than a physical change because in a chemical change

• Chemicals are used

• Molecules do not physically touch

• A new substance is formed and in a physical change no new substance is formed

• The change can be seen but in a physical change it cannot

What is a precipitate, and what does its formation show?

• A solid substance formed when two clear solutions are mixed, indicating a chemical change

• A gas formed during a physical change, indicating a change in state

• A liquid formed during a chemical change, indicating a change in temperature

• Bubbles of carbon dioxide gas form, indicating a chemical reaction

For the remaining questions, determine if the example is either a physical or chemical change. Write "P" in the blank for a physical change and a "C" for a chemical change. Melting Butter

(a)  

For the remaining questions, determine if the example is either a physical or chemical change. Write "P" in the blank for a physical change and a "C" for a chemical change. Burning a marshmallow

(a)  

For the remaining questions, determine if the example is either a physical or chemical change. Write "P" in the blank for a physical change and a "C" for a chemical change. Dissolving sugar in tea

(a)  

For the remaining questions, determine if the example is either a physical or chemical change. Write "P" in the blank for a physical change and a "C" for a chemical change. Melting chocolate

(a)