2. Acids, Bases, and pH

3. Properties of acids 1. Sour taste

4. 2. Contain hydrogen, react with active metals to give off H 2 gas

5. 3. Change the color of indicators

6. 4. React with bases to produce salts and water water e.g. e.g. 2NaOH + H 2 SO 4 → 2H 2 O + Na 2 SO 4 2NaOH + H 2 SO 4 → 2H 2 O + Na 2 SO 4

7. 5. Acids are electrolytes

8. Traditional definition of an acid A cmpd. That contains hydrogen and ionizes in aqueous soln. to form hydrogen ions (H + ) A cmpd. That contains hydrogen and ionizes in aqueous soln. to form hydrogen ions (H + )

9. Common acids HCl – hydrochloric acid HCl – hydrochloric acid H 2 SO 4 – sulfuric acid H 2 SO 4 – sulfuric acid HC 2 H 3 O 2 – acetic acid HC 2 H 3 O 2 – acetic acid HNO 3 – nitric acid HNO 3 – nitric acid H 3 PO 4 – phosphoric acid H 3 PO 4 – phosphoric acid

10. Sulfuric acid #1 industrial chemical #1 industrial chemical Fertilizers, petroleum refining, …… Fertilizers, petroleum refining, …… Used as a measure of a country’s economy Used as a measure of a country’s economy

11. Acetic acid Dilute acetic acid is vinegar Dilute acetic acid is vinegar

12. Acid Precipitation Combustion of fossil fuels Combustion of fossil fuels –Is the main cause of acid precipitation

13. 4.6 4.3 4.1 4.3 4.6 4.3 Europe North America

14. Bases

15. Properties of bases 1. Bitter taste

16. 2. Feel slippery to the skin 3. Change color of indicators

17. 4. React with acids to produce water and salts e.g. e.g. 2NaOH + H 2 SO 4 → 2H 2 O + Na 2 SO 4 2NaOH + H 2 SO 4 → 2H 2 O + Na 2 SO 4 5. Bases are electrolytes

18. Traditional definition of a base OH - producer OH - producer

19. Neutralization reactions Reaction of hydronium ions (H 3 O + ) and hydroxide (OH - ) ions to form water Reaction of hydronium ions (H 3 O + ) and hydroxide (OH - ) ions to form water H 3 O + + OH -  2H 2 O H 3 O + + OH -  2H 2 O HCl + NaOH  H 2 O + NaCl HCl + NaOH  H 2 O + NaCl (NaCl is a salt)

20. Common bases

21. Sodium hydroxide (NaOH), also known as lye or caustic soda, is a caustic metallic base. It is widely used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents. Worldwide production in 1998 was around 45 million tons. (NaOH), also known as lye or caustic soda, is a caustic metallic base. It is widely used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents. Worldwide production in 1998 was around 45 million tons.NaOHcausticbasechemicalbasepulppapertextilesdrinking water soapsdetergents tonsNaOHcausticbasechemicalbasepulppapertextilesdrinking water soapsdetergents tons

22. pH scale

23. pH - log [H + ] - log [H + ] e.g. if [H + ] = 1 x 10 -8 M e.g. if [H + ] = 1 x 10 -8 M pH = 8 pH = 8

24. If [H + ] = 3.4 x 10 -5 find pH = -[(log 3.4 + log 10 -5 )] = -[(log 3.4 + log 10 -5 )] = -[(0.53) + (-5)] = -[(0.53) + (-5)] = -(0.53 – 5) = -(0.53 – 5) = 4.47 = 4.47

25. If the pH is 2 what is the [H + ] pH = -log [H + ] pH = -log [H + ] log [H + ] = -pH log [H + ] = -pH [H + ] = antilog (-pH) [H + ] = antilog (-pH) = antilog (-2) = antilog (-2) = 1 x 10 -2 M

26. If the pH is 6.4 what is [H + ] [H + ] = antilog (-pH) [H + ] = antilog (-pH) = antilog (-6.4) = antilog (-6.4) = 4.0 x 10 -7 M

27. If the pH is 5.4 what is [H + ] [H+] = antilog (-pH) = antilog (-5.4) = antilog (-5.4) = 4.0 x 10 -6 M

28. [H + ] [OH - ] = 1 x 10 -14 Therefore if [OH - ] = 1 x 10 -10 Therefore if [OH - ] = 1 x 10 -10 pH = 4 pH = 4 if [OH - ] = 1 x 10 -7 if [OH - ] = 1 x 10 -7 pH = 7 pH = 7

29. Diprotic acid Can donate (2) protons (H + ) per molecule Can donate (2) protons (H + ) per molecule e.g. H 2 SO 4 e.g. H 2 SO 4

30. Triprotic Donates (3) protons Donates (3) protons e.g. H 3 PO 4 e.g. H 3 PO 4

31. Normality (N ) = (molarity) x (whole # factor) = (molarity) x (whole # factor) # equivalents solute / L of solution # equivalents solute / L of solution

32. What is the normality of a soln w/ 1 mol H 2 SO 4 dissolved in 1 L of soln? 2 equivalents x 1 mol H 2 SO 4 = 2 equivalents 1 mol H 2 SO 4 1 L 1 L = 2 N H 2 SO 4

33. Titration Controlled addition & measurement of amt. of soln. of a known conc. That is required to react completely with a measured amt. of soln. of unknown conc. Controlled addition & measurement of amt. of soln. of a known conc. That is required to react completely with a measured amt. of soln. of unknown conc.

35. Graph of titration results

36. Saponification hydrolysis of an ester under basic conditions to form an alcohol and the salt of a carboxylic acid. Saponification is commonly used to refer to the reaction of a metallic alkali (base) with a fat or oil to form soap. hydrolysis of an ester under basic conditions to form an alcohol and the salt of a carboxylic acid. Saponification is commonly used to refer to the reaction of a metallic alkali (base) with a fat or oil to form soap. hydrolysisesterbasicalcoholsaltcarboxylic acidbasefatoilsoap hydrolysisesterbasicalcoholsaltcarboxylic acidbasefatoilsoap