1. HCl   copper sulfate   sulfur dioxide   sodium hydroxide   hydrochloric acid   Hint Hint       2. Na2CO3   magnesium oxide   sulfuric acid   ammonia   sodium carbonate   Hint       3. CO2   carbon dioxide   sodium chloride   potassium permanganate   water   Hint       4. HNO3   hydrogen peroxide   water   carbon disulfide   nitric acid   Hint       5. CuSO4   ammonium sulfate   sodium carbonate   copper sulfate   sulfur dioxide   Hint       6. H2O   hydrochloric acid   water   sodium carbonate   sodium chloride   Hint       7. CS2   carbon disulfide   sodium chloride   magnesium oxide   sodium hydroxide   Hint