2. 1. LEARN THESE DIATOMIC MOLECULES: O 2 H 2 N 2 F 2 Cl 2 Br 2 I 2 2. The same number of atoms of each element appearing in reactants must appear in the products. 3. The subscripts of a formula cannot be changed to balance the equation. Each compound must retain its stableness via oxidation states. 4. Choose compound with greatest number of atoms first. 5. Balance by placing necessary coefficients in front of entire molecules. NO SUBSCRIPT CHANGES!

3. 6. Be certain each side of equation has same number of atoms of each type. 7. Make sure coefficients are in lowest whole number ratios. 8. Polyatomic ions usually stay intact, but multiple polyatomic ions may be separated. 9. (aq.) stands for aqueous which is Latin for water solution: (g) gas (l) liquid (s) solid (c) crystalline solid

4.   means “yields” and shows direction of action  ∆ above arrow shows heat has been added   shows reaction is reversible  MINOH: try Metals first, then Ions, then Nonmetals, and Oxygen, then Hydrogen last

5. C 8 H 18 + O 2  CO 2 + H 2 O C 8 H 18 + O 2  __ CO 2 + __ H 2 O C 8 H 18 + __ O 2  __ CO 2 + __ H 2 O __ C 8 H 18 + __ O 2  __ CO 2 + __ H 2 O

6. H 2 CrO 4 + AgNO 3  Ag 2 CrO 4 + HNO 3 (aq) (aq) (s) (aq) Chromic + Silver  Silver + Nitric Acid Nitrate Chromate Acid 1, 2, 1, 2 Double displacement

7. Cu(NO 3 ) 2  CuO + NO 2 + O 2 (aq) (s) (g) (g) Copper (II)  Copper (II) + Nitrogen + Oxygen Nitrate Oxide Dioxide Gas 2, 2, 4, 1 Decomposition

8. AlBr 3 + Cl 2  AlCl 3 + Br 2 (aq) (g) (aq) (g) Aluminum + Chlorine  Aluminum + Bromine Bromide Gas Chloride Gas 2, 3, 2, 3 Single Displacement

9. P 4 + O 2 + H 2 O  H 3 PO 4 (s) (g) (aq) (aq) Phosphorus + Oxygen + Water  Phosphoric (free) gas acid 1, 5, 6, 4 Synthesis

10. sodium permanganate + sulfuric acid  sodium sulfate + manganese (VII) oxide + water NaMnO 4 + H 2 SO 4  Na 2 SO 4 + Mn 2 O 7 + H 2 O (aq) (aq) (aq) (s) (l) 2, 1, 1, 1, 1 Double Displacement

11. Th(NO 3 ) 4 + K 3 PO 4  Th 3 (PO 4 ) 4 + KNO 3 (aq) (aq) (s) (aq) Thorium + Potassium  Thorium + Potassium Nitrate Phosphate Phosphate Nitrate 3, 4, 1, 12 Double Displacement

12. sulfur trioxide + nitric acid  sulfuric acid + dinitrogen pentoxide SO3 + HNO3  H2SO4 + N2O5 (g) (aq) (aq) (g) 1, 2, 1, 1 Double Displacement

13. NH 4 NO 3 + Ca(OH) 2  Ca(NO 3 ) 2 + NH 3 + H 2 O (aq) (aq) (aq) (g) (l) Ammonium + Calcium  Calcium + Ammonia + water Nitrate Hydroxide Nitrate 2, 1, 1, 2, 2 Double Displacement

14. sodium chloride + potassium iodide  NaCl + KI  ________ + _________ (aq) (aq) (?) (?) Does a reaction take place?

15. CuSO 4 + H 3 PO 4  _____ + ______ (aq) (aq) A) 3, 1, 2, 1 B) 3, 1, 1, 3 C) 2, 3, 3, 2 D) 3, 2, 1, 3 E) 2, 3, 3, 1 ((D)) Copper (II) + Phosphoric  Copper (II) + Sulfuric Sulfate Acid Phosphate Acid

16. Mg(OH) 2 + H 3 PO 4  _____ + ______ (aq) (aq) A. 1, 1, 1, 1 B. 3, 2, 1, 3 C. 2, 3, 1, 6 D. 2, 3, 1, 1 E. 3, 2, 1, 6 ((E.)) Magnesium + Phosphoric  Magnesium + Water Hydroxide Acid Phosphate

17. CuCl2 + Na3PO4  _____ + ______ (aq) (aq) A. 1, 2, 1, 2 B. 2, 3, 1, 6 C. 2, 3, 1, 1 D. 3, 2, 1, 6 E. 1, 1, 1, 1 ((D)) Copper (II) + Sodium  Copper (II) + Sodium Chloride Phosphate Phosphate Chloride

18. Potassium + Nickel (II)  _____ + ______ Permanganate Nitrate A. 2, 1, 2, 1 B. 2, 1, 3, 1 C. 1, 2, 1, 2 D. 1, 2, 1, 3 E. 1, 1, 1, 1 ((A)) KMnO 4 + Ni(NO 3 ) 2  KNO 3 + Ni(MnO 4 ) 2

19. KMnO 4 + Na 2 C 2 O 4 + H 2 SO 4  K 2 SO 4 + Na 2 SO 4 + MnSO 4 + CO 2 + H 2 O Balance this equation and show your atom inventory and earn a grade pass.