1. Questions 231
1a. What do the formulas, arrow, and plus signs in a chemical equation tell you?

2. Questions 231
1b. Compare and Contrasting How are reactants and products treated the same in a chemical reaction? How are they treated differently?

3. Questions 231
2a. Explaining How does the idea of atoms explain the principle of conservation of matter?

4. Questions 231
2b. Applying Concepts If the total mass of the products of a reaction is 250g, what was the total mass of the reactants?

5. Questions 231
3a. Reviewing What are three types of chemical reactions?

6. Questions 231
3b. Inferring What is the smallest possible number of products in a decomposition reaction?

7. Questions 231 3c. Classifying Classify the following reaction:
P4O10 + 6H2O  4H3PO4

8. Questions 231 Practice __Fe2O3 + __C  __Fe + __CO2
__SO2 + __O2  __SO3

9. Questions 229 Balancing Chemical Equations
1. Balance the equation for the reaction of sodium metal (Na) with oxygen gas (O2), forming sodium oxide (Na2O).

10. Questions 229 Balancing Chemical Equations
2. Balance the equation for the reaction of tin (Sn) with chlorine gas (Cl2), forming tin chloride (SnCl2).

11. Questions 239 Controlling Chemical Equations
1a. What is activation energy?

12. Questions 239 Controlling Chemical Equations
1B. Describing What role does activation energy play in chemical reactions?

13. 1c. Making Generalizations Look at the diagram in Figure 13, and make a generalization about activation energy in exothermic and endothermic reactions.

14. Questions 239 Controlling Chemical Equations
2a. Identifying What are four ways that chemists can control the rates of chemical reactions?

15. Questions 239 Controlling Chemical Equations
2b. Applying Concepts Which would react more quickly in a chemical reaction: a single sugar cube or an equal mass of granulated sugar crystals? Explain.

16. Figure P. 236 Energy Changes in Chemical Equations Both exothermic and endothermic reactions need energy to get started. Draw and compare the graphs. Figure P. 239 Enzyme Action After a reaction, an enzyme molecule is unchanged.