1. Unit 8 Acids and Bases

2. Naming acids 1)Acids not containing oxygen: hydro______ ic acid HF, HCl, HBr, HI, HCN, H 2 S 2)Acids containing polyatomic ions Polyatomic ion ends in ate Acid named ________ic acid HNO 3, H 2 SO 4, H 3 PO 4, HClO 4, HClO 3 Polyatomic ion ends in ite Acid name ________ous acid HNO 2, H 2 SO 3, H 2 PO 3, HClO 2, HClO Must be aqueous!!!!!

3. Naming bases Common bases are hydroxides – NaOH, KOH, Ca(OH) 2, Al(OH) 3 Some bases have common names – NH 3

4. Acid Base Theories [273-277] Arrhenius :Acids have H + Bases have OH - Bronsted- Lowry: Acids: proton (H + or H 3 O + ) donors Bases: proton acceptors Lewis: Acids are electron pair acceptors Bases are electron pair donors

5. Bronsted-Lowry Acids/Bases [273-276] Conjugate acid/base pairs HA + B → A - + BH + OR HA + B ↔ A - + BH +

6. Bronsted-Lowry Acids/Bases [273-276] Exercises 3,2,1 page 276 Many substances can act as either an acid or a base depending on the environment they are in. They are often referred to as amphoteric or amphiprotic

7. Bronsted-Lowry Acids/Bases [273-276] Many substances can act as either an acid or a base depending on the environment they are in. They are often referred to as amphoteric or amphiprotic HCO 3 - is amphoteric

8. Lewis Acids/Bases [276-277] BF 3 + NH 3 → BF 3 NH 3 Definitions Dative bond or coordinate bond Ligand Complex ion

9. Lewis Acids/Bases [276-277] Exercises 4-6 page 277

10. Acid Base Indicators [278-279] Change color in acidic or basic environment Litmus paper – Blue in basic, red in acidic Other indicators have other color changes

11. Properties of Acids [279-281] Monoprotic acids have one donateable hydrogen Diprotic acids have two donateable hydrogens Triprotic acids have three donateable hydrogens. Name and tell mono, di, or triprotic – H 3 PO 4, CH 3 COOH, H 2 SO 4, HNO 3 1) taste sour 2) change color of Litmus paper: blue to red

12. Properties of Acids [279-281] 1) taste sour 2) change color of Litmus paper: blue to red

13. Properties of Acids [279-281] 3) react with active metals to produce hydrogen Acid + metal → salt + hydrogen

14. Properties of Acids [279-281] 4)neutralize bases Acid + base → salt + water Acid + metal oxide → salt + water Neutralization is always exothermic

15. Properties of Acids [279-281] 5)react with carbonates to produce CO 2 Acid + carbonate → salt + water + carbon dioxide

16. Properties of Acids [279-281] Exercises 7-9 page 281

17. Properties of Bases taste bitter taste and “soapy feel” neutralize acids change color of Litmus paper: red to blue

18. Strong vs. Weak There are strong acids and weak acids There are strong bases and weak bases Strong and weak do not equal concentrated and dilute Strong and weak denotes extent of dissociation or ionization

19. http://www.pearsonplaces.com.au/Portals/0/ studentlounge/IB_ChemSL/SelfIonisation/tuto r/f15/1504.html http://www.pearsonplaces.com.au/Portals/0/ studentlounge/IB_ChemSL/SelfIonisation/tuto r/f15/1504.html

20. Strength of Acids/Bases Strong Acids to memorize – HCl – HBr – HI – HNO 3 – H 2 SO 4 – HClO 4 – HClO 3

21. Strength of Acids/Bases Strong bases to memorize – Hydroxides of column 1A and 2A Ca and below

22. Strength of Acids/Bases [282-283] Strong acids

23. Strength of Acids/Bases [282-283] Strong bases

24. Strength of Acids/Bases [282-283] Weak acids

25. Strength of Acids/Bases [282-283] weak base

26. Distinguishing between strong and weak acids and bases [283-284] 1) Electrical conductivity

27. Distinguishing between strong and weak acids and bases [283-284] 2) Rate of reaction

28. Distinguishing between strong and weak acids and bases [283-284] 3) pH

29. Distinguishing between strong and weak acids and bases [283-284] 4) Amount of acid or base needed to neutralize

30. questions Which has higher concentration of H + ions? – HCl or NaOH – HNO 3 or HNO 2 – H 2 CO 3 or CH 3 COOH Which is the best conductor of electricity? – HF or KOH – KOH or HBr – HBr or HF – NaOH or NH 3

31. questions Which would react with Zn the most vigorously? – Strong acid, weak acid, strong base, weak base Which would produce the most bubbles with Na 2 CO 3 ? – Strong acid, weak acid, strong base, weak base Exercises 10-12 page 284

32. pH scale [284-286]

33. pH is an abbreviation for “power of hydrogen, pH is a logarithmic scale. pH = - log [H 3 O + ] pOH = - log [OH - ] pH + pOH = 14 K w = [OH -][H 3 O +] = 1.0 X 10 -14 [H 3 O + ] = 10 -pH [OH - ] = 10 -pOH

34. pH practice [H + ] [OH - ] pHpOHAcid/base/neutral 1 x 10 -3 1 x 10 -8 12 0.0001 12 0.000001

35. pH practice What is the pH of 0.01 M HBr? What is the pH of 1 x 10 -3 HCl? What is the pH of 1 x 10 -3 H 2 SO 4 ? What is the pH of 0.01 M NaOH? What is the pH of 1 x 10 -3 KOH? What is the pH of 1 x 10 -3 Ba(OH) 2 ?

36. Remember As pH changes by units of 1, the [H + ] concentration changes by a factor of 10 An equal concentration of a weak acid will not have as low of a pH as a strong acid An equal concentration of a weak base will not have as high of a pH as a strong base [H + ] = [strong acid] and [OH - ] = [strong base]*

37. pH questions Exercises 13-15 page 286

38. pH questions What pH would 0.001 M HCl have? What pH would 0.001 M CH 3 COOH have? A strong acid is diluted by a factor of 10. What will happen to the pH? 0.01 M HCl pH = 2 0.01 M H 2 SO 4 pH = 1.7 Why the difference? 0.01 M CH 3 COOH pH = 3.4.

39. Acid Base Titration Technique used to determine concentration of an acid or base

40. Titration Curve of Strong Acid

41. Titration Curve of Strong Base

42. Titration Curve of Weak Acid

43. Titration Curve of Polyprotic Acid

44. How to Interpret Titration Curves find the equivalence point – it is the steepest part of the curve where the pH rises the fastest – the equivalence point can be used to determine the equivalent weight (molar mass) of the acid

45. equivalence point mid point A Typical Titration Curve