Balancing Chemical Equations

1. Balancing Chemical Equations Section 10.1

2. Objectives • Balance skeleton equations • Balance word equations

3. Key Terms • Chemical reaction • Reactants • Products • Coefficient • Chemical equation

4. Review (VERY IMPORTANT!) • What are the diatomic elements?

5. Review (VERY IMPORTANT!!) • How many atoms of each element are in the following: • HCl • Na2S • Ca3P2 • Mg(NO3)2

6. Chemical Equations • Represents a chemical reaction • Uses an arrow to separate reactants from products • Reactants • Starting substances • Left side • Products • Ending substances • Right side

7. 2 Types of Equations • Skeleton • Gives formulas • H2 + O2  H2O • Word • Gives names • Hydrogen and oxygen react to form water

8. Balancing • Chemical equations MUST be BALANCED • Law of Conservation of Matter • Number of atoms of each element must be equal on both sides of arrow • Only COEFFICIENTS can be used

9. Coefficients • Number in front of a formula • How many atoms of each element are there in the following: • 2HCl • 4Na2S • 3Ca3P2 • 2Mg(NO3)2

10. Skeleton Examples • H2 + Cl2 HCl • CO + O2  CO2 • KClO3  KCl + O2

11. Word Examples • Iron (III) chloride reacts with sodium hydroxide to form iron (III) hydroxide and sodium chloride • Carbon disulfide reacts with oxygen, producing carbon dioxide and sulfur dioxide • Zinc and sulfuric acid react to form hydrogen and zinc sulfate