General, Organic, and Biological Chemistry

Fourth EditionKaren Timberlake

8.2Electrolytes and Nonelectrolytes

Chapter 8Solutions

© 2013 Pearson Education, Inc.Lectures

© 2013 Pearson Education, Inc. Chapter 8 Section 2 2

In water, strong electrolytes separate into ions making

solutions that conduct electricity. weak electrolytes produce a few ions. nonelectrolytes produce molecules, not ions.

Electrolytes, Nonelectrolytes

© 2013 Pearson Education, Inc. Chapter 8 Section 2 3

Solutes that are strong electrolytes dissociate 100% or break up into positive and

negative ions in water. form aqueous solutions (aq) when dissolved in

water that will conduct an electrical current. H2O 100% ions

NaCl(s) Na+(aq) + Cl(aq) H2O

CaBr2(s) Ca2+(aq) + 2Br(aq)

Strong Electrolytes

© 2013 Pearson Education, Inc. Chapter 8 Section 2 4

Complete each of the following equations for strongelectrolytes dissolving in water.

Learning Check

© 2013 Pearson Education, Inc. Chapter 8 Section 2 5

Complete each of the following equations for strongelectrolytes dissolving in water.

Solution

© 2013 Pearson Education, Inc. Chapter 8 Section 2 6

Solutes that are weak electrolytes dissolve in water mostly as molecules. dissolve in water forming a few ions. produce solutions that conduct electricity weakly.

Weak Electrolytes

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Nonelectrolytes

Solutes that are nonelectrolytes dissolve as molecules in

water. do not produce ions in water. form solutions that do not

conduct an electrical current.

© 2013 Pearson Education, Inc. Chapter 8 Section 2 8

Classification of Solutes in Aqueous Solutions

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Equivalents

An equivalent (Eq) is the amount of that ion equal to 1mole of positive or negative electrical charge (+ or –). Forexample, 1 mole of Na+ ions and 1 mole of Cl− ions are each 1

equivalent or 1000 milliequivalents (mEq) because they each contain 1 mole of charge, and

ions with a charge of 2+ or 2−, contain 2 equivalents for each mole.

1 mole Na+ = 1 Eq1 mole Ca2+ = 2 Eq1 mole S2− = 2 Eq

© 2013 Pearson Education, Inc. Chapter 8 Section 2 10

Equivalents of Electrolytes

© 2013 Pearson Education, Inc. Chapter 8 Section 2 11

Electrolytes in Body Fluids

Electrolytes play an important role in maintaining theproper function of the cells and organs in the body.

Sodium ions regulate water content and carry electrical impulses through the nervous system.

Potassium ions are involved in the transmission of electrical impulses and help maintain a regular heartbeat.

Bicarbonate ions help maintain blood pH.

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Electrolytes in Blood Plasma

© 2013 Pearson Education, Inc. Chapter 8 Section 2 13

Learning Check 1. In 1 mole of Fe3+, there are

A. 1 Eq. B. 2 Eq. C. 3 Eq.

2. In 2.5 mole of SO42−, there are

A. 2.5 Eq. B. 5.0 Eq. C. 1.0 Eq.

3. An intravenous bottle contains only NaCl. If the Na+ ion produces 34 mEq/L, the Cl− ion producesA. 34 mEq/L. B. 0 mEq/L. C. 68 mEq/L.

© 2013 Pearson Education, Inc. Chapter 8 Section 2 14

Solution 1. In 1 mole of Fe3+, there are 3 equivalents (Eq).

C. 3 Eq

2. In 2.5 mole of SO42−, there are 5 equivalents.

B. 5.0 Eq

3. An intravenous bottle contains only NaCl. If the Na+ ion produces 34 mEq/L, the Cl− ion producesA. 34 mEq/L.