Reactions in Aqueous Solution Chapter 4 Part 1

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Reactions in Aqueous Solution Chapter 4 – Part 1

Reactions in Aqueous Solution Chapter 4 – Part 1

Solutions A solution is a homogenous mixture The solute is present in the smaller

Solutions A solution is a homogenous mixture The solute is present in the smaller amount The solvent is present in the larger amount Solution Solvent Solute Soft drink (l) H 2 O Sugar, CO 2 Air (g) N 2 O 2, Ar, CH 4 Soft Solder (s) Pb Sn 4. 1

An electrolyte is a substance that, when dissolved in water, results in a solution

An electrolyte is a substance that, when dissolved in water, results in a solution that can conduct electricity. A nonelectrolyte is a substance that, when dissolved, results in a solution that does not conduct electricity. nonelectrolyte weak electrolyte strong electrolyte 4. 1

Conduct electricity in solution? Cations (+) and Anions (-) Strong Electrolyte – 100% dissociation

Conduct electricity in solution? Cations (+) and Anions (-) Strong Electrolyte – 100% dissociation Na. Cl (s) H 2 O Na+ (aq) + Cl- (aq) Weak Electrolyte – not completely dissociated CH 3 COOH CH 3 COO- (aq) + H+ (aq) 4. 1

Hydration is the process in which an ion is surrounded by water molecules arranged

Hydration is the process in which an ion is surrounded by water molecules arranged in a specific manner. d- d+ H 2 O

Electrolytes n n Substances that dissociate into ions when dissolved in water allow water

Electrolytes n n Substances that dissociate into ions when dissolved in water allow water to conduct electricity. A nonelectrolyte may dissolve in water, but it does not dissociate into ions when it does so.

Electrolytes and Nonelectrolytes Soluble ionic compounds tend to be electrolytes.

Electrolytes and Nonelectrolytes Soluble ionic compounds tend to be electrolytes.

Electrolytes and Nonelectrolytes Molecular compounds tend to be nonelectrolytes, except for acids and bases.

Electrolytes and Nonelectrolytes Molecular compounds tend to be nonelectrolytes, except for acids and bases.

Strong Electrolytes Are… n Strong acids

Strong Electrolytes Are… n Strong acids

Strong Electrolytes Are… n n Strong acids Strong bases

Strong Electrolytes Are… n n Strong acids Strong bases

Strong Electrolytes Are… n n n Strong acids Strong bases Soluble ionic salts

Strong Electrolytes Are… n n n Strong acids Strong bases Soluble ionic salts

Precipitation Reactions When one mixes ions that form compounds that are insoluble (as could

Precipitation Reactions When one mixes ions that form compounds that are insoluble (as could be predicted by the solubility guidelines), a precipitate is formed.

Acids: n n Substances that increase the concentration of H+ when dissolved in water

Acids: n n Substances that increase the concentration of H+ when dissolved in water (Arrhenius). Proton donors (Brønsted–Lowry).

Bases: n n Substances that increase the concentration of OH− when dissolved in water

Bases: n n Substances that increase the concentration of OH− when dissolved in water (Arrhenius). Proton acceptors (Brønsted–Lowry).

Neutralization Reactions Generally, when solutions of an acid and a base are combined, the

Neutralization Reactions Generally, when solutions of an acid and a base are combined, the products are a salt and water. HCl (aq) + Na. OH (aq) Na. Cl (aq) + H 2 O (l)

Gas-Forming Reactions n The expected product decomposes to give a gaseous product (CO 2

Gas-Forming Reactions n The expected product decomposes to give a gaseous product (CO 2 or SO 2). Ca. CO 3 (s) + HCl(aq) Ca. Cl 2(aq) + CO 2(g) + H 2 O (l) Na. HCO 3(aq) + HBr(aq) Na. Br(aq) + CO 2(g) + H 2 O(l) Sr. SO 3(s) + 2 HI(aq) Sr. I 2(aq) + SO 2(g) + H 2 O(l)

Oxidation-Reduction Reactions n n An oxidation occurs when an atom or ion loses electrons.

Oxidation-Reduction Reactions n n An oxidation occurs when an atom or ion loses electrons. A reduction occurs when an atom or ion gains electrons.

Displacement Reactions n n In displacement reactions, ions oxidize or reduce an element. The

Displacement Reactions n n In displacement reactions, ions oxidize or reduce an element. The ions, then, are reduced or oxidized.