1. Starter 2/6  Write the word equation from the following description: Zinc metal is added to hydrochloric acid to create zinc chloride and hydrogen gas.

2. Ch. 8 Chemical Equations and Reactions 8.1b Balancing Equations and Writing Formula Equations

3. Balancing Equations  Skittle method works great...  But there is also MINOH 1. Metals 2. Ions, specifically of the polyatomic variety (see p. 210 for a refresher) 3. Non-metals (except oxygen & hydrogen) 4. Oxygen & Hydrogen are saved for last

4. Writing Equations 1. Write word equation to help you organize reactants and products 2. Include symbols showing states of each reactant and product 3. Write the correct formula for each (review chapter 7) 4. Balance the equation

5. Example 1  Description: Zinc metal is added to hydrochloric acid to create zinc chloride and hydrogen gas.  Word Equation: zinc + hydrochloric acid  zinc chloride + hydrogen

6. Example 1  Formula Equation: Zn (s) + HCl(aq)  ZnCl 2 (aq) + H 2 (g)  Balanced Formula Equation Zn (s) + 2HCl(aq)  ZnCl 2 (aq) + H 2 (g)

7. Example 2  Solid calcium metal reacts with water to form aqueous calcium hydroxide and hydrogen gas.  calcium + water  calcium hydroxide + hydrogen  Ca(s) + H 2 O(l)  Ca(OH) 2 (aq) + H 2 (g)  Ca(s) + 2H 2 O(l)  Ca(OH) 2 (aq) + H 2 (g)

8. Example 3  solid zinc metal reacts with aqueous copper (II) sulfate to produce solid copper metal and aqueous zinc sulfate  zinc + copper (II) sulfate  copper + zinc sulfate  Zn(s) + CuSO 4 (aq)  Cu(s) + ZnSO 4 (aq)

9. Example 4  Aqueous hydrogen peroxide decomposes to produce oxygen and water  hydrogen peroxide  oxygen + water  H 2 O 2 (aq)  O 2 (g) + H 2 O(l)  2H 2 O 2 (aq)  O 2 (g) + 2H 2 O(l)

10. Example 5  Solid copper metal reacts with aqueous silver nitrate to produce solid silver metal and aqueous copper (II) nitrate  copper + silver nitrate  silver + copper (II) nitrate

11. Example 5  Cu(s) + AgNO 3 (aq)  Ag(s) + Cu(NO 3 ) 2 (aq)  Cu(s) + 2AgNO 3 (aq)  2Ag(s) + Cu(NO 3 ) 2 (aq)

12. Example 6  Carbon dioxide gas is bubbled through water containing solid barium carbonate, creating aqueous barium bicarbonate  carbon dioxide + water + barium carbonate  barium bicarbonate  CO 2 (g) + H 2 O(l) + BaCO 3 (s)  Ba(HCO 3 ) 2 (aq)

13. Example 7  Acetic acid solution is added to a solution of magnesium bicarbonate to create water, carbon dioxide gas, and aqueous magnesium acetate.  acetic acid + magnesium bicarbonate  water + carbon dioxide + magnesium acetate  HCH 3 COO(aq) + Mg(HCO 3 ) 2 (aq)  H 2 O(l) + CO 2 (g) + Mg(CH 3 COO) 2 (aq)  2HCH 3 COO(aq) + Mg(HCO 3 ) 2 (aq)  2H 2 O(l) + 2CO 2 (g) + Mg(CH 3 COO) 2 (aq)