Changes in matter Review

Which of the following describes what happens during a chemical reaction?

• Matter is created and destroyed

• Matter is neither created nor destroyed

• Matter is destroyed

Which change below is a chemical change?

• One kind of matter changes phases

• One kind of matter changes into another kind of matter with different properties

• One kind of matter keeps its density and properties

Look at the chemical equation below.

C + 0_{2 =} CO₂

Carbon * Oxygen = Carbon Dioxide

What is the product of the reaction?

(a)  

Which of the following is an example of combustion?

• a log burning in a fire

• a dry sponge expanding in water

• a container of milk souring to cottage cheese

A scientist used universal indicator paper to test an unknown substance. The indicator paper turned red. What can the scientist conclude about the substance.

• It is a weak acid.

• It is a strong acid.

• It is a strong base.

What bacteria- killing susbtance did Alexander Fleming accidentaly discover that become an important life-saving medicine?

• insulin

• penicilin

• aspirin

Look at the illustration.

This tent is made from a polymer developed in chemical laboratory. What is the name of the polymer?

• silk

• wool

• nylon

• cotton

What kind of reaction occurs when two compounds split apart and the parts switch places, as shown in the reaction below?

FeS + 2HCL = FeCL + H₂S

• reduction reaction

• combination reaction

• replacement reaction

What should you do FIRST before using chemicals at home?

• Put on safety goggles

• Ask a friend what to do

• Read the directions

Explain how treated rubber, which is heated and has sulfur added, has different properties from untreated rubber. Why is treated rubber more desirable