Ch.5 Classification & Balancing of Chemical Reactions
Back
- Identify the oxidized reactant, the reduced reactant, the oxidizing agent, and the reducing agent in the following reactions: a. Fe(s)+Cu₂+(aq) → Fe₂+(aq)+Cu(s) b. Mg(s)+Cl₂(g) → MgCl₂(s) c. 2 Al(s)+Cr₂O₃(s) → 2 Cr(s) + Al₂O₃(s)
Problem 8
- Potassium, a silvery metal, reacts with bromine, a corrosive, reddish liquid, to yield potassium bromide, a white solid. Write the balanced equation, and identify the oxidizing and reducing agents.
Problem 9
- Assume that the mixture of substances in drawing (a) undergoes a reaction. Which of the drawings (b)–(d) represent a product mixture consistent with the law of conservation of mass? a.
Problem 16
b.
c.
d. - Reaction of A (green spheres) with B (blue spheres) is shown in the following diagram:
Problem 17
Which equation best describes the reaction? a. A₂ + 2 B → A₂B₂ b. 10 A + 5 B₂ → 5 A₂B₂ c. 2 A + B₂ → A₂B₂ d. 5 A + 5 B₂ → 5 A₂B₂
- An aqueous solution of a cation (represented as blue spheres in the diagram) is allowed to mix with a solution of an anion (represented as green spheres) and the following result is obtained:
Problem 20
Which combinations of cation and anion, chosen from the following lists, are compatible with the observed results? Explain. Cations: Na+, Ca2+, Ag+, Ni2+ Anions: Cl−, CO2−3, CrO2−4, NO−3
- What is meant by the term 'balanced equation'?
Problem 22
- Why is it not possible to balance an equation by changing the subscript on a substance, say from H₂O to H₂O₂?
Problem 23
- Which of the following equations are balanced? Balance those that need it. a. CaC₂+2 H₂O→Ca(OH)₂+C₂H₂ b. C₂H₈N₂+2 N₂O₄→2 N₂+2 CO₂+4 H₂O c. 3 MgO +2 Fe→Fe₂O₃+3 Mg d. N₂O→N₂+O₂
Problem 27
- When sodium metal is placed in water, the following change occurs: Sodium, Na (s) + Water, H2O (l) → Hydrogen, H₂ (g) + Sodium hydroxide, NaOH (aq) a. Identify the reactants and products and their physical states
Problem 44
- In each of the following, tell whether the substance gains electrons or loses electrons in a redox reaction: a. An oxidizing agent b. A reducing agent c. A substance undergoing oxidation d. A substance undergoing reduction
Problem 49
- High temperature combustion processes, such as in combustion engines and coal-fired power plants, can result in the reaction of nitrogen and sulfur with oxygen to form nitrogen oxides (NO𝓍) and sulfur oxides (SO𝓍), where x can vary. These NO𝓍 and SO𝓍 compounds subsequently undergo further reaction in the atmosphere to create acidic compounds that contribute to acid rain. a. Do some research to determine the common products that are formed (i.e., what are the values of x) for the reactions of N and S with oxygen. Write balanced equations for these reactions.
Problem 73
- Many pharmaceuticals are marketed with the designation 'HCl' appended to the name of the drug. What does the 'HCl' mean? What type of reaction would be involved in converting a drug to the HCl form? What are the advantages of this form of the drug?
Problem 75
- Cobalt(II) chloride, a blue solid, can absorb water from the air to form cobalt(II) chloride hexahydrate, a pink solid. The equilibrium is so sensitive to moisture in the air that CoCl₂ is used as a humidity indicator. Write a balanced equation for the equilibrium. Be sure to include water as a reactant to produce the hexahydrate.
Problem 93
