1 7.2 Electrolytes and Nonelectrolytes Chapter 7 Solutions Copyright © 2009 by Pearson Education, Inc.

2 In water, strong electrolytes produce ions and conduct an electric current. weak electrolytes produce a few ions. nonelectrolytes do not produce ions. Solutes and Ionic Charge Copyright © 2009 by Pearson Education, Inc.

3 Strong electrolytes dissociate in water, producing positive and negative ions. conduct an electric current in water. in equations show the formation of ions in aqueous(aq) solutions. H 2 O 100% ions NaCl(s) Na + (aq) + Cl − (aq) H 2 O CaBr 2 (s) Ca 2+ (aq) + 2Br − (aq) Strong Electrolytes

4 Complete each for strong electrolytes in water. H 2 O A. CaCl 2 (s) 1) CaCl 2 (s) 2) Ca 2+ (aq) + Cl 2 − (aq) 3) Ca 2+ (aq) + 2Cl − (aq) H 2 O B. K 3 PO 4 (s) 1) 3K + (aq) + PO 4 3− (aq) 2) K 3 PO 4 (s) 3) K 3 + (aq) + P 3− (aq) + O 4 − (aq) Learning Check

5 Complete each for strong electrolytes in water: H 2 O A. CaCl 2 (s) 3) Ca 2+ (aq) + 2Cl − (aq) H 2 O B. K 3 PO 4 (s) 1) 3K + (aq) + PO 4 3− (aq) Solution

6 A weak electrolyte dissociates only slightly in water. in water forms a solution of a few ions and mostly undissociated molecules. HF(g) + H 2 O(l) H 3 O + (aq) + F - (aq) NH 3 (g) + H 2 O(l) NH 4 + (aq) + OH - (aq) Weak Electrolytes

7 Nonelectrolytes dissolve as molecules in water. do not produce ions in water. do not conduct an electric current. Copyright © 2009 by Pearson Education, Inc.

8 Equivalents An equivalent (Eq) is the amount of an electrolyte or an ion that provides 1 mole of electrical charge (+ or -). 1 mole of Na + = 1 equivalent 1 mole of Cl − = 1 equivalent 1 mole of Ca 2+ = 2 equivalents 1 mole of Fe 3+ = 3 equivalents

9 Electrolytes in Body Fluids In replacement solutions for body fluids, the electrolytes are given in milliequivalents per liter (mEq/L). Ringer’s Solution Na mEq/LCl − 155 mEq/L K + 4 mEq/L Ca 2+ 4 mEq/L The milliequivalents per liter of cations must equal the milliequivalents per liter of anions.

Electrolytes in Body Fluids 10 Copyright © 2009 by Pearson Education, Inc.

11 Learning Check A. In 1 mole of Fe 3+, there are 1) 1 Eq.2) 2 Eq. 3) 3 Eq. B. In 2.5 moles of SO 4 2−, there are 1) 2.5 Eq.2) 5.0 Eq. 3) 1.0 Eq. C.An IV bottle contains NaCl. If the Na + is 34 mEq/L, the Cl − is 1) 34 mEq/L.2) 0 mEq/L. 3) 68 mEq/L.

12 Solution A. 3) 3 Eq. B. 2) 5.0 Eq. 2.5 mole SO 4 2− x 2 Eq = 5.0 Eq 1 mole SO 4 2− C. 1) 34 mEq/L