1. Bonding and Chemical Formulas
Chapter 23 Review

2. 1. What are the reactants in a chemical reaction?

3. 2. A chemical reaction that gives off energy (usually as heat and/or light) is which type of reaction?

4. 3. Name two signs of a chemical change.

5. 4. A chemical reaction that absorbs (takes in) energy, usually getting colder, is which type of reaction?

6. 5. What are the products in a chemical reaction?

7. Balance the following chemical equation.
6. Calcium oxide, CaO, reacts with sulfur dioxide to form calcium sulfite, CaSO3.

8. Balance the following chemical equation.
7. Methanol, CH3OH, breaks down (decomposes) into carbon monoxide and hydrogen gas, H2.

9. Balance the following chemical equation.
8. When heated, tantalum metal reacts with chlorine gas, Cl2, to form tantalum pentachloride, TaCl5.

10. Balance the following chemical equation.
9. Nitric acid, HNO3, reacts with hydrogen sulfide, H2S, to form nitrogen dioxide, water,
and sulfur.

11. Balance the following chemical equation.
10. Aluminum sulfate, Al2(SO4)3, decomposes to yield aluminum oxide, Al2O3, and sulfur trioxide, SO3.

12. Stop

13. 1. What are the reactants in a chemical reaction?
Beginning materials

14. 2. A chemical reaction that gives off energy (usually as heat and/or light) is which type of reaction?
Exothermic

15. 3. Name two signs of a chemical change.
Production of smoke
Production of gas
Change in color
Change in temperature

16. 4. A chemical reaction that absorbs (takes in) energy, usually getting colder, is which type of reaction?
Endothermic

17. 5. What are the products in a chemical reaction?
The ending materials

18. Balance the following chemical equation.
6. Calcium oxide, CaO, reacts with sulfur dioxide to form calcium sulfite, CaSO3.

19. Balance the following chemical equation.
7. Methanol, CH3OH, breaks down (decomposes) into carbon monoxide and hydrogen gas, H2.

20. Balance the following chemical equation.
8. When heated, tantalum metal reacts with chlorine gas, Cl2, to form tantalum pentachloride, TaCl5.

21. Balance the following chemical equation.
9. Nitric acid, HNO3, reacts with hydrogen sulfide, H2S, to form nitrogen dioxide, water,
and sulfur.

22. Balance the following chemical equation.
10. Aluminum sulfate, Al2(SO4)3, decomposes to yield aluminum oxide, Al2O3, and sulfur trioxide, SO3.