Chemical Reactions Unit Exam

According to the law of conservation of mass, matter cannot be created or ________

• destroyed

• created

When a new substance forms as a result of a chemical reaction, what type of change has occurred?

• Chemical Change

• Physical Change

Which is NOT an indication of a chemical change?

• Temperature Change

• Shape Change

• Formation of a precipitate

• Production of light

What is the left part of a chemical equation called?

2H_{2 +} O₂ --> 2H₂O

• Reactants

• Yields

• Products

• Chemical Equation

What is the right part of a chemical equation called...

2H_{2 +} O₂ --> 2H₂O

• Reactants

• Yields

• Products

• Chemical Equation

True or False

In a chemical reaction, no new atoms are created, and no atoms are destroyed.

• TRUE

• FALSE

When materials combine to form new compounds it is a chemical change. Which example is a chemical change?

• baking powder fizzing
• water boiling
• ice melting
• sugar cube dissolving

When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic?

• a change of color
• a change of state
• a temperature decrease
• a temperature increase

What types of reactions absorb and release heat?

• acidic and basic
• endothermic and exothermic
• endothermic and heat transfusion
• covalent and ionic

Which of the following is a chemical change?

• water freezes to form ice
• sugar dissolves in water
• gasoline burns in a car engine
• a piece of metal expands when it is heated