Chemical Reactions

Chemistry is

• the study of matter and how matter changes

• mixing liquids together and watching what happens

The only sure evidence for a chemical reaction is

• color

• the production of one or more new substances

A material used to decrease the rate of a chemical reaction is a(n)

• inhibitor

• fuel

CaCO3 represents a chemical

• symbol

• formula

Which is the correct chemical equation for the following statement?

Sodium reacts with oxygen in a 2 to 1 ratio to produce sodium oxide

• 4 Na + O2 = 2 Na2O

• 4 Sd + X2 = 2 Sd2X

The principle of conservation of mass is true

• for no reactions at all

• for reactions in both open and closed systems

In chemical reactions, what does the principle of conservation of mass mean?

• matter is not created or destroyed

• matter is not changed

Chemicals that act as biological catalysts by speeding up reactions in living things are called

• fuels

• enzymes

Which of the following is an example of how to supply activation energy to begin a reaction?

• heat the reaction flask on a hot plate

• Add an inhibitor

A bottle of hydrogen peroxide that eventually turns into a bottle of water and oxygen gas is an example of a

• replacement reaction

• decomposition reaction