Unit 4: Chapter 9: End of Chapter Problems

9.4: Although water is classified as a nonelectrolyte, in reality it is an extremely weak electrolyte and therefore cannot conduct electricity. Nevertheless, it can be dangerous to operate electrical appliances with wet hands. Explain.
The water could react with the other molecules – dissolving them into aqueous solutions and creating a possibility for a stronger electrolyte to form. Therefore, if the water on your hands were to react with other molecules that could generate electricity if they form strong electrolytes.

9.5: Identify the species present in aqueous solutions of the following strong electrolytes:
(a) LiF
(b)NH₄NO
(c) CaBr₂
(d) Na₂CO₃
(a) Strong
(b) Weak
(c)
(d)

9.11: Which of the following diagrams best represents the hydration of NaCl when dissolved in water? The Cl⁻ ion is larger in size than the Na⁺ ion. ***Page 349 for picture***
C

9.12: Identify each of the following substances as a strong electrolyte, weak electrolyte, or nonelectrolyte:
(a) H₂O
(b)KCl
(c) HNO₃
(d) HC₂H₃O₂
(e) C₁₂H₂₂O₁₁
(a) EXTREMELY weak
(b) Strong
(c)
(d)
(e)

9.13: Identify each of the following substances as a strong electrolyte, weak electrolyte, or nonelectrolyte:
(a) Ba(NO₃)₂
(b) Ne
(c) NH₃
(d) NaOH
(e) HF
(a)
(b)
(c)
(d)
(e) Strong

9.17: Two aqueous solutions of AgNO₃ and NaCl are mixed. Which of the following diagrams best represents the mixture? ***Picture on page 350***

9.20: Characterize the following compounds as soluble or insoluble in water:
(a) CaCO₃
(b)ZnSO₄
(c) Hg(NO₃)₂
(d) HgSO₄
(e) NH₄ClO₄
(a)Insoluble
(b)Soluble
(c)Soluble
(d)Insoluble
(e)Soluble

9.21: Characterize the following compounds as soluble or insoluble in water:
(a) Ca₃(PO₄)₂
(b)Mn(OH)
(c)AgClO₃
(d)K₂S
(e)Pb₃(PO₄)₂
(a)Insoluble
(b)Insoluble
(c)Soluble
(d)Soluble
(e)Insoluble

9.15:
(a) What is the difference between a molecular equation and an ionic equation?
(b) Between an ionic equation and a net ionic equation?
(c) What is the advantage of writing net ionic equations?
(a) Molecular Equation: All compounds represented by chemical formulas
Ionic Equation: Compounds represented by their ions
(b) Ionic Equation: All ions represented
Net Ionic Equation: Only active ions represented (no spectator ions in equation)
(c) With Net Ionic Equations, you are able to isolate the action of the reaction.

9.23: Write ionic and net ionic equations for the following reactions:
(a) AgNO₃(aq) + Na₂SO₄(aq) →
(b) BaCl₂(aq) + ZnSO₄(aq) →
(c) (NH₄)₂CO₃(aq) + CaCl₂(aq) →
(a) 2Ag⁺(aq) + SO₄²⁻(aq) → Ag₂SO₄
(b)
(c)

9.25: Which of the following processes will likely result in a precipitation reaction?
(a) Mixing a NaNO₃ solution with a CuSO₄ solution
(b) Mixing a BaCl₂ with a K₂SO₄ solution
(c) Mixing a AgNO₃ solution with a LiC₂H₃O₂ solution.

Write a net ionic equation for each combination.

(a) Not a Precipitation Reaction
No net ionic equation
(b)
(c)