Question | Answer |
4.1 Classify the following as either a mixture or a pure substance: (a.) An egg (b.) A gold nugget (c.) A bottle of HNO₃ (d.) Lemonade dissolved in water | (a.) Mixture (b.) Pure substance (c.) Pure substance (d.) Mixture |
4.2 Reclassify everything in question #1 as an element, compound, homogeneous mixture, or heterogeneous mixture. | (a.) Heterogeneous mixture (b.) Element (c.) Compound (d.) Homogeneous mixture |
4.3 Classify the substances following question #3 on page 132 as physical or chemical changes. | Physical: a, c, e Chemical: b, d |
4.4 What is the chemical formula of nitrogen gas? | N₂ |
4.5 Is the following equation balanced? CaF₂(aq) + 2NH₄Cl (aq) → CaCl₂ (aq) + NH₄F (aq) | No. |
4.6 Balance the following equation: HCl (aq) + Zn (s) → ZnCl₂ (aq) + H₂ (g) | 2HCl + Zn → ZnCl₂ + H₂ |
4.7 In an automobile, nitrogen from the air reacts with oxygen in the engine to make nitrogen monoxide, a toxic pollutant. Write the balanced chemical equation for this reaction. | N₂ + O₂ → 2NO |
4.8 Liquid heptene, C₇H₁₀, can react with gaseous hydrogen to make liquid heptane, C₇H₁₆. Write the balanced chemical equation for this reaction. | C₇H₁₀ + 3H₂ → C₇H₁₆ |
4.9 Balance the following equation: C₇H₁₆ (l) + O₂ (g) → CO₂ (g) + H₂O (g) | C₇H₁₆ (l) + 11O₂ (g) → 7CO₂ (g) + 8H₂O (g) |
4.10 Balance the following equation: CO₂ (g) + H₂O (l) → C₁₂H₂₄O₁₂ (s) + O₂ (g) | 12CO₂ (g) + 12H₂O (l) → C₁₂H₂₄O₁₂ (s) + 12O₂ (g) |