Unit 7 - Chemical Reactions And Energy

5 Questions | By Haszshe | Updated: Mar 21, 2022 | Attempts: 415

Chemical reactions are the processes that lead to the transformation of one set of chemical substances to another. Energy is a physical property that must be transferred to an object in order to perform work on or to heat it.

Questions and Answers

1.

Which of the following is a chemical reaction?
- A.
  
  Rust forming on a car body
- B.
  
  Water evaporating from salt water leaving salt crystals
- C.
  
  Water freezing into ice
- D.
  
  Dew forming on grass
2.

When iron combines with oxygen and water in the air to form rust, what substance in the reaction is the product?
- A.
  
  Rust
- B.
  
  Iron
- C.
  
  Oxygen
- D.
  
  Water
3.

As a result of the experiment of Lavoisier, you know that in a chemical reaction the mass of the products ______.
- A.
  
  Is twice as great as the mass of the reactants
- B.
  
  Is less than the mass of the reactants
- C.
  
  Always equals the mass of the reactants
- D.
  
  Cannot be predicted based on the mass of the reactants
4.

Which of the following symbols in a chemical equation means "produces"?
- A.
  
  +
- B.
  
  [p]
- C.
  
  (aq)
- D.
5.

A(n) ______ is a substance that speeds up a chemical reaction without being permanently changed itself.
- A.
  
  Catalyst
- B.
  
  Inhibitor
- C.
  
  Exotherm
- D.
  
  Endotherm