Acid, Bases & Salt Video

1. Acid, Bases & Salt Video • Post Test • Neutralization • Base • Anion • Electrolytes • False • False • True • False • False • Post Test • bitter, slippery, high pH • Acids donate hydrogen, Bases accept Hydrogen • An easy way to gauge is something is a strong/weak acid or base • Pre Test • True • False • True • True • False • False • True • True • False • False

2. Ch. 8Solutions, Acids, & Bases III. Particles in Solution “Like Dissolves Like” Electrolytes

3. A. “Like Dissolves Like” • Polar substances will only dissolve in polar liquids • Rubbing alcohol and water • Nonpolar substances will only dissolve in nonpolar liquids • Oil and butter • Substances that aren’t the same don’t mix. • Oil and water

4. NONPOLAR NONPOLAR POLAR POLAR A. “Like Dissolves Like” • Detergents • polar “head” with long nonpolar “tail” • can dissolve both types (polar and nonpolar)

5. B. Electrolyte • An electrolyte is a substance that when dissolved in water form ions • Electrolytes get their name from the fact that the conduct electricity in water. • Example: salt dissolved in water • Many sports drinks contain “electrolytes” which are salts dissolved in water

6. - + - - + + acetic acid salt sugar B. Electrolytes Electrolyte Weak Electrolyte Non- Electrolyte solute exists as ions only Easily conducts electricity solute exists as ions and Molecules Slightly conducts electricity solute exists as molecules only Does NOT conduct electricity

7. B. Electrolytes • Dissociation • separation of +/- ions when an ionic compound dissolves in water

8. B. Electrolytes • Ionization • breaking apart of polar covalent molecules into ions when dissolving in water

9. Ch. 8Solutions, Acids, & Bases IV. Intro to Acids & Bases Definitions Properties Uses

10. A. Acids • Acids contain at least one hydrogen atom that can be removed when the acid is dissolved in water. • These form hydronium ions, H3O+. • Also called a proton donor HCl+ H2O  H3O+ + Cl–

11. A. Bases • Bases form hydroxide ions (OH-) in a water solution. • a proton acceptor NH3+ H2O  NH4+ + OH-

12. A. Indicators • Indicators are an organic substance that changes color in an acid or base. • Examples: • litmus - red/blue • phenolphthalein - colorless/pink • goldenrod - yellow/red • red cabbage juice - pink/green

13. sour taste pH less than 7 corrosive electrolytes turn litmus red react with metals to form H2 gas bitter taste pH greater than 7 corrosive electrolytes turn litmus blue slippery feel B. Properties ACIDS BASES

14. H3PO4 –phosphoric acid - soft drinks, fertilizer, detergents H2SO4 – sulfuric acid - fertilizer, car batteries HCl – hydrochloric acid - gastric juice HC2H3O2 – acetic acid - vinegar C. Uses ACIDS

15. NaOH – sodium hydroxide -lye, drain and oven cleaner Mg(OH)2 – magnesium hydroxide - laxative, antacid NH3 –ammonia - cleaners, fertilizer C. Uses BASES

16. Ch. 8Solutions, Acids, & Bases V. Strength of Acids & Bases Strength vs. Concentration Strong vs. Weak pH

17. A. Strength vs. Concentration • Strong and weak – tells how easy the acid or base dissociates in solution. • Concentration – The amount of acid or base in a solution. • It is possible to have a dilute concentration of a strong acid that would be less harmful than a concentrated weak acid.

18. A. Strength of Acids & Bases • The strength of an acid or base depends on how completely a compound separates into ions when dissolved in water. • Ions can carry an electric charge so a strong acid will carry more electricity than weak acid.

19. - - + + B. Strong vs. Weak • Strong Acid/Base • 100% ions in water • strong electrolyte • HCl, HNO3, NaOH, LiOH • Weak Acid/Base • few ions in water • weak electrolyte • HC2H3O2, NH3

20. B. Strong Acids • Acids that ionize almost completely in a solution are strong acids. • Ex: HCl, HNO3, and H2SO4 • They have a very low pH (0-1).

21. B. Strong Bases • Bases that dissociate completely in a solution are strong bases. • Ex: NaOH • They have a very high pH (13-14)

22. 14 0 7 INCREASING BASICITY INCREASING ACIDITY NEUTRAL C. pH Scale • pH (potential of Hydrogen) • a measure of the concentration of H+ ions in a solution • measured with a pH meter or an indicator with a wide color range (0-14)

23. C. pH Scale pH of Common Substances

24. ConcepTest • Which of the following "molecular" pictures best represents a concentrated solution of the weak acid HA? A B

25. ConcepTest • Is the following statement TRUE or FALSE? • A strong acid has a lower pH than a weak acid. • True- • But: Strong/weak refers to amount of ionization whereas pH refers to concentration of H+.

26. Ch. 8Solutions, Acids, & Bases VI. Neutralization • Neutralization Reaction

27. A. Neutralization Reaction • Chemical reaction between an acid and a base. • Products are a salt (ionic compound) and water.

28. = A. Neutralization Reaction ACID + BASE  SALT + WATER HCl + NaOH NaCl + H2O Neutralization does not always mean pH = 7.

29. KOH + HNO3 H2O + KNO3 A. Neutralization Reaction Acid Base Salt HNO3 KOH KNO3