1 Chapter 8: Acids and Bases Acids & Bases Ionization of Water pH Acid-Base Reactions

2 Remember Electrolytes Na + NaCl Na + Cl - C 6 H 12 O 6 IonicCovalent

3 Acids H+H+ HC 2 H 3 O 2 H+H+ C 2 H 3 O 2 1- H+H+ H-Cl H+H+ Cl - WeakStrong Lots of IonsOnly a few Ions

4 Acids Acid Acid = gives hydrogen ions in water H+H+ H-Cl H+H+ Cl - HCl H + + Cl - hydrogen ion

5 Acids H-Cl + H-O-H + Cl - hydronium ion Cl - H-Cl Acid Acid = gives hydrogen ions in water

6 Common Acids Battery Acid Stomach Acid Coca Cola Carbonated Water Vinegar Citrus fruits Vitamin C Grapes Aspirin H 2 SO 4 HCl H 3 PO 4 H2CO3H2CO3 HC2H3O2HC2H3O2 H3C6O7H8H3C6O7H8 HC6O6H7HC6O6H7 H2C4O6H4H2C4O6H4 H2C9O4H8H2C9O4H8 Sulfuric Acid Hydrochloric Acid Phosphoric Acid Carbonic Acid Acetic Acid Citric Acid Ascorbic Acid Tartaric Acid Acetyl Salicylic Acid

7 Naming Acids Binary Acids: Hydrogen & non metal. ex. HCl HBr H 2 S hydro- ______________-ic Acid HCl Hydrochloric acid H 2 S Hydrosulfuric acid

8 Naming Oxygen containing acids Oxoacids: Hydrogen, oxygen, and a nonmetal ex. HNO 3 HNO 2 H 2 SO 4 The higher number of O’s ______________-ic Acid HNO 3 = Nitric Acid The lower number of O’s ______________ -ous ending. HNO 2 = Nitrous Acid

9 THE COMMON -IC ACIDS H 2 SO 4 SULFURIC ACID HNO 3 NITRIC ACID H 2 CO 3 CARBONIC ACID H 3 PO 4 PHOSPHORIC ACID HClO 3 CHLORIC ACID

10 This system works great when there are only 2 oxidation states for the central non-metal atom. (high & low) hypo- When acids have a central non-metal atom that can have more than 2 oxidation states, the one lower than ous is prefixed with hypo-.

11 EXAMPLE: H 2 SO 4 H 2 SO 4 (S= +6)Sulfuric acid H 2 SO 3 H 2 SO 3 (S= +4)Sulfurous acid H 2 SO 2 H 2 SO 2 (S= +2)hyposulfurous acid

12 The highest of these four acids is prefixed with a per- (from hyper meaning above). HClO 4 perchloric acid HClO 3 chloric acid HClO 2 chlorous acid HClOhypochlorous acid

13 H 2 SO 4 HCl H 3 PO 4 H 2 CO 3 HC 2 H 3 O 2 H 3 C 6 O 7 H 8 HC 6 O 6 H 7 H 2 C 4 O 6 H 4 H 2 C 9 O 4 H 8 Common Acids Battery Acid Stomach Acid Coca Cola Carbonated Water Vinegar Citrus fruits Vitamin C Grapes AspirinStrong 100% ionization100% ionization Strong electrolyteStrong electrolyte Weak Partial ionizationPartial ionization Weak electrolyteWeak electrolyte Taste sourTaste sour

14 Acids H-Cl + H-O-H + Cl - Cl - H-Cl H+H+ HC 2 H 3 O 2 C 2 H 3 O 2 1- HC 2 H 3 O 2 H-C 2 H 3 O 2 + H-O-H + C 2 H 3 O 2 -

15 Acids H+H+ H-Cl H+H+ Cl - WeakStrong Lots of IonsOnly a few Ions H+H+ HC 2 H 3 O 2 C 2 H 3 O 2 1- HC 2 H 3 O 2

16 Base Base = gives hydroxide ions in water. (Arrhenius definition) = takes hydrogen ions in water. (Brönsted definition) Bases NaOH Na + + OH - OH - Na + NaOH

17 Common Bases Lye, Drano Potash Cleaners Milk of Magnesia Baking soda Tums /Rolaids Limestone, shells Soaps Detergents NaOH KOH NH 3 or NH 4 OH Mg(OH) 2 NaHCO 3 CaCO 3 NaC 16 O 2 H 31 NaC 12 O 4 H 25 S Sodium Hydroxide Potassium Hydroxide Ammonia Magnesium Hydroxide Sodium Bicarbonate Calcium Carbonate Sodium Palmitate Sodium Lauryl Sulfate

18 Common Bases Lye, Drano Potash Cleaners Milk of Magnesia Baking soda Tums /Rolaids Limestone, shells Soaps Detergents NaOH KOH NH 3 Mg(OH) 2 NaHCO 3 CaCO 3 NaC 16 O 2 H 31 NaC 12 O 4 H 25 S Strong 100% ionization100% ionization Strong electrolyteStrong electrolyte Weak Partial ionizationPartial ionization Weak electrolyteWeak electrolyte Taste bitterTaste bitter Feel SlipperyFeel Slippery

19 The Six Strong Acids HCl (aq) HBr (aq) HI (aq) H 2 SO 4(aq) HNO 3(aq) HClO 4(aq) Hydrochloric acid Hydrobromic acid Hydroiodic acid Sulfuric acid Nitric acid Perchloric acid

20 The Strong Bases Group 1A Metal Hydroxides: Ba(OH) 2(aq) Sr(OH) 2(aq) LiOH (aq) NaOH (aq) KOH (aq) Ca(OH) 2(aq)

21 HNO 3 + H 2 O H 3 O + + NO 3 - Water is Amphoteric Acid donates a protonBase takes a proton NH 3 NH 3 + H 2 O NH OH - NH 3 Acid donates a protonBase takes a proton HNO 3 Acid donates a protonBase takes a proton AcidBase

22 NH 3 + H 2 O NH OH -

23 conjugate pair H 2 CO 3 + H 2 O HCO H 3 O + Conjugate Acid - Base Pairs conjugate pair ACID BASE conj acid conj base Polyprotic acids Polyprotic acids = Acids that donate >1 H+: H 2 CO 3, H 2 SO 4, and H 3 PO 4.

24 H2OH2OH2OH2O Conjugate Acid - Base Pairs Acid - Base H 2 CO 3 HCO 3 1- CO 3 2- H3O+H3O+H3O+H3O+ HO 1- H 3 PO 4 H 2 PO 4 1- PO 4 3- HPO 4 2- Acid - Base Acid - Base Acid - Base

25 HPO H 2 O PO H 3 O + H 2 PO H 2 O HPO H 3 O + H+’s donate 1 at a time. Example: Phosphoric acid H 3 PO 4 + H 2 O H 2 PO H 3 O +

26 H 2 O + H 2 O OH – + H 3 O + Ionization of Water conjugate pair ACID BASE conj acid conj base conjugate pair

27 H 2 O + H 2 O OH – + H 3 O + Ion product constant of Water ACID BASE conj acid conj base 0.000,000,1M = 1 x M 0.000,000,1M Neutral: if [H 3 O + ] = [OH – ] Acidic: if [H 3 O + ] > [OH – ] Basic: if [H 3 O + ] < [OH – ] [ ]  moles/liter Note: [ ]  moles/liter

28 H 2 O + H 2 O OH – + H 3 O + Ion product constant of Water ACID BASE conj acid conj base 0.000,000,1M = 1 x M 0.000,000,1M K w = [H 3 O + ] [OH – ] = 1 x [H 3 O + ] [OH – ] = (1 x )(1 x ) =1 x (1 x )(1 x ) =1 x (1 x )(1 x ) =1 x (1 x )(1 x ) =1 x

29 pH = 1 x 10 –pH pH = pH = – log [H + ] HCl HC 2 H 3 O 2 H2OH2O NaOH 0.000,000,1 M = 1 x 10 –7 M [H + ] 0.000,1 M = 1 x 10 –4 M 0.000,000,000,001 M = 1 x 10 –12 M 100 M = 1 x 10 2 M ,000,001 M = 1 x 10 –9 M = 1 x 10 –9 M NH 3 Neutral Acidic Basic

30 pH = 1 x 10 -pH pH = pH = - log [H+] HCl HC 2 H 3 O 2 H2OH2O NaOH 0.000,000,1 M = 1 x M [H+] 0.000,1 M = 1 x M 0.000,000,000,001 M = 1 x M 100 M = 1 x 10 2 M ,000,001 M = 1 x M = 1 x M NH 3 Neutral Acidic Basic Citric Acid 0.000,76 M = 7.6 x M = 7.6 x M

31 pH = 1 x 10 –pH pH = pH = – log [H+] HC 2 H 3 O 2 [H+] 0.000,1 M = 1 x 10 –4 M Citric Acid M = 1 x 10 –3 M 0.000,76 M = 7.6 x 10 –4 M = 7.6 x 10 –4 M 3 pH = – log (7.6 x 10 –4 ) = 3.1

32 pH [H + ] = 1 x 10 -pH pH = pH = - log [H+] 0.000,000,04 M 4.0 x M = 4.0 x M BakingSoda = 1 x M 3.2 x M = 3.2 x M pH = - log (4.0 x ) = 7.4 Cleaner = 1 x M 5.0 x M = 5.0 x M Blood

33 pH of some common materials Substance pH Substance pH 1 M HCl0.0 1 M HCl0.0 Lemon juice2.3 Lemon juice2.3 Coffee5.0 Coffee5.0 Pure Water7.0 Pure Water7.0 Blood Blood Milk of Magnesia M NaOH M NaOH 14.0

34 HOH + H 2 O OH – + H 3 O + pH and pOH ACID BASE conj acid conj base 0.000,000,1M = 1 x M 0.000,000,1M [H 3 O + ] [OH – ] = 1 x (1 x )(1 x ) =1 x = 14 pH + pOH = = 14

35 pH and pOH pH[H+] [OH – ] pOH [H 3 O + ] [OH – ] = 1 x pH + pOH = 14 pH = - log [H 3 O + ] pOH = - log [OH – ] = [H 3 O + ] = 1 x 10 -pH 1x = 1.7x10 -4 M

36 pOH examples Determine the following: pOH = -log[OH - ] or 14 - pH 1. pOH of 1.7x10 -4 M NaOH pOH = 3.8 pH = pOH of 5.2x M H + pH = 11.2 pOH = [OH - ], if the pH is 4.5 pOH = 9.5 [OH - ] = 3.2x M

37 pH paper: Litmus paper: Anthocyanins: red cabbage, cranberries, roses… Phenolphthalein:Turmeric: pH meter: Pigments:

38 Indicator examples Acid-base indicators undergo a color change at a known pH. bromthymol blue phenolphthaleinmethyl red

39 Acid Reactions HCl + Zn  Cl – Zn H+H+H+H+ ZnCl 2 + H 2 Acid MetalSalt

40 Activity series of metals potassium sodium potassium sodium calcium magnesium aluminum zinc chromium magnesium aluminum zinc chromium iron nickel tin lead iron nickel tin lead copper silver platinum gold copper silver platinum gold Hydrogen Al + Fe +3  Fe + Al +3 Fe + H +  Fe +3 + H 2 increasing reactivity Element give e’s to ion lower on list

41 Activity series of metals Reacts violently with cold water Reacts slowly with cold water Reacts very slowly with steam but quite reactive in acid Reacts moderately with high levels of acid Unreactive in acid potassium sodium potassium sodium calcium magnesium aluminum zinc chromium magnesium aluminum zinc chromium iron nickel tin lead iron nickel tin lead copper silver platinum gold copper silver platinum gold Hydrogen increasing reactivity

42 Acid-Base Reactions HCl + NaOH  OH – Cl – Na + H+H+H+H+ NaCl + HOH AcidBaseSalt Water Neutralization: Strong Acid + Strong Base

43 Acid-Base Reactions H 2 SO 4 + KOH  OH – SO 4 -2 K+K+K+K+ H+H+H+H+ K 2 SO 4 + HOH AcidBaseSalt Water 22

44 Acid-Base Reactions HC 2 H 3 O 2 + NaHCO 3 HCO 3 1- C 2 H 3 O 2 1- Na + H+H+H+H+ NaC 2 H 3 O 2 + H 2 CO 3 AcidBase Salt H 2 O + CO 2(g) Vinegar & Baking Soda

45 Acid-Base Reactions Acid Rain on Marble Cream of Tartar & Baking Soda H 2 C 4 H 6 O 6 + NaHCO 3 Na 2 C 4 H 6 O 6 + H 2 CO 3 H 2 O + CO 2(g) AcidBaseSalt H 2 SO 4 + CaCO 3 CaSO 4 + H 2 CO 3 H 2 O + CO 2(g) AcidBaseSalt

46 Cleopatra's Needle in New York City Central Park (originally erected in the Egyptian city of Heliopolis on the orders of Thutmose III, around 1450 B.C.). Erected in New York in 1881.

47 Effects of Acid Rain Exterior of old church in Germany

48

49 Acid-Base Reactions Lemon on Fish H 3 C 6 H 8 O 7 + R-NH 2 C 6 H 8 O R-NH 3 1+ AcidBase Salt

50 Buffers Weak acid + Weak baseWeak acid + Weak base Resists change in pHResists change in pH NaC 2 H 3 O 2 HC 2 H 3 O 2 NaC 2 H 3 O 2 + H 2 O HCl NaOH NaCl + HC 2 H 3 O 2

51 Logarithms As with exponents, this is a way of working with very large and very small numbers log n the abbreviation for the term logarithm n is the base log 10 common logs based on 10 the only type we will be using the 10 is usually omitted We will only be using base 10 logs

52 Logarithms For ‘whole’ numbers, the common log and the exponent in scientific notation are the same. log(1000) = = 10 3 logs of other numbers are no integers but the idea is the same. log(1500) = =

53 Logarithms A positive log represents a number greater than one. log(13456)= A negative log represents a number smaller than one. log( ) = You CAN’T take the log of a negative value. log( -235 )= error Chemistry for Allied health

54 Logarithms value log(value) The sign tells us if the number is larger or smaller than one. The number before the decimal point tells us where the decimal point would be in scientific notation. The number after the decimal point tells us what the number is.

55 Use your calculator! If you have a log button, you’re all set. If it does not have this button Buy one that does! Each calculator can have its own method for entering logs. If you don’t know what to do your calculator manual should give examples. Logarithms E -2

56 If your calculator has a ln button - Don’t use it. Its for taking natural logs. This is different than base 10. Logarithms E -2

57 Antilogs The opposite of logs. Sometimes you need to know what the original value was. Taking the antilog of the value will do this. Your calculator should have a 10 x button E -2