1. Arrhenius acids Produce H + ions in solutions H + produced by acids is the only positive ion in acidic solutions Properties of acids are related to properties of H + ions they produce H + ions produced by acids usually combine with H 2 O to become H 3 O + H + + H 2 O  H 3 O + Hydrogen ionhydronium ion Arrhenius Bases Produce OH - ions in solutions OH - produced by bases is the only negative ion in basic solutions Properties of bases are related to properties of OH - ions they produce Most bases are ionic compounds

2. Properties of Acids Electrolytes Change color of indicators React with bases to produce water and salt Produce H + as only positive ion in solution Contain MORE H + than OH - in solutions When added to water, they increase H + concentration of the water When added to water, they decrease OH - concentration of the water When added to water, they decrease pH Have pH LESS than 7 Turn blue litmus red Have no effect on phenolphthalein (stays colorless) Taste sour React with certain metals to produce salt and hydrogen gas

3. Properties of Bases Electrolytes Change color of indicators React with acids to produce water and salt Produce OH - as the only negative ion in solution Contain more OH - than H + in solutions When added to water, decrease H + ion concentration of the water When added to water, increase OH - ion concentration of the water When added to water, increase pH Have pH greater than 7 Turn red litmus blue Turn phenolphthlein from colorless to pink Taste bitter and feels slippery

4. Neutral substances pH of 7 Have equal amount of H + to OH - ions

5. Alternate theory defines acids and bases by their ability to donate or accept a proton (H + or hydrogen ion) during certain chemical reactions Alternate theory of acids An acid is a substance that can DONATE A PROTON during a reaction Alternate theory of bases A base is a substance that can ACCEPT A PROTON during a reaction H 2 O + NH 3  OH - + NH 4 + acidbaseconjugate conjugate base acid

6. To determine Arrhenius acids LOOK for one of the common acids on Table K LOOK for a formula containing H and another nonmetal

7. Practice Which of these substances is considered an Arrhenius acid? 1)KOH2) CH 3 OH3) HNO 3 4) NH 3 Which substance will dissolve in water to produce H 3 O + as the only positive ion in solution? 1) HF2) NaOH3) NH 4 OH4) KCl

8. To determine if a substance is Arrhenius base or to determine which substance will produce OH - LOOK for one of the common bases on Table L LOOK for a formula containing a metal and OH

9. Practice Which formula is an Arrhenius base? 1)HCl2) He3) CH 3 OH4) KOH An aqueous solution of which of these substances contains hydroxide ions as the only negative ion? 1) C 2 H 5 OH2) NaCl3) Mg(OH) 2 4) H 2 SO 4

10. Acidic solutions contain MORE H + ions than OH - [H + ] > [OH - ] HCl and HNO 3 Neutral solutions and pure water contain EQUAL amounts of H + and OH - [H + ] = [OH - ] Pure H 2 O and NaCl Basic solutions contain MORE OH - ions [OH - ] > [H + ] NaOH and NH 3

11. To determine which substance will produce more H + ions than OH - ions LOOK for a formula or name of an acid (Table K) To determine which formula will produce more OH - ions than H + ions LOOK for a formula or name of a base (Table L) Practice Which of these solutions contains higher concentrations of H 3 O + ions than OH - ions? 1)NH 3 (aq)2) HNO 3 (aq) 3) C 6 H 12 O 6 (aq) Which substance will produce a solution with more hydroxide ions than hydrogen ions? 1) LiOH2) KCl3) HCl4) CH 3 COOH

12. pH is a measure of the H + ion or the H 3 O + ion concentration of a solution. A pH scale ranges in value from 1 – 14. Acids and bases can be defined by their pH values. Acids are substances with pH values LESS than 7 Neutral substances have pH = 7 Bases are substances with pH values GREATER than 7

13. To determine substance if pH given is less than 7 LOOK for a formula or name of an acid To determine substance if pH given is more than 7 LOOK for a formula or name of a base To determine substance with pH equal to 7 LOOK for a formula or name of a neutral substance Practice Substance X is dissolved in water to produce a solution with a pH of 2. Substance X is most likely 1)Lithium hydroxide3) methanol 2)Ammonia4) nitric acid

14. Acid – Base indicators are substances that can change color in the presence of an acid or bas Acid and bases can be defined by the changes caused on these indicators. Phenolphthalein is a colorless indicator ACIDS have no effect on phenolphthalein BASES change colorless phenolphthalein to pink Litmus is an indicator ACIDS change litmus paper to RED BASES change litmus paper to BLUE

16. Practice Which substance would change colorless phenolphthalein to pink? 1)H 2 O2) KOH3) CH 3 COOH 4) HCl Which substance would likely change bromcresol green from yellow to blue? 1)CH 3 COOH2) CH 3 OH3) NaOH 4) NaCl A solution turns litmus red to blue. The pH of this solution could be 1)12) 143) 7 4) 9 A solution contains more hydronium ions than hydroxide ions. Which statement is also true of this solution? 1)Its pH is 4, and phenolphthalein will be colorless 2)Its pH is 4, and phenolphthalein will be pink 3)Its pH is 10, and phenolphthalein will be colorless 4)Its pH is 10, and phenolphthalein will be pink