Equations. M = n/v. M 1 V 1 = M 2 V 2 if the moles are the same n 1 n 2 you can cancel out the n s. ph = -log [H + ] poh = -log [OH - ] ph + poh = 14

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2 Equations M = n/v M 1 V 1 = M 2 V 2 if the moles are the same n 1 n 2 you can cancel out the n s. ph = -log [H + ] poh = -log [OH - ] ph + poh = 14 [H 3 O + ] = 10^-pH [OH - ] = 10^-pOH [H 3 O + ] [OH - ] = 1.0 x 10-14

3 Strong Electrolytes Strong electrolytes or completely Three classes of strong electrolytes

4 Properties of Acids taste change the colors of indicators turn litmus paper red react with metals to generate react with and to form salts and water aqueous solutions conduct

5 Properties of Bases taste feel change colors of indicators turn litmus paper blue react with to form salts and water aqueous solutions conduct electricity

6 Ex. 1) HCl, Ca(OH) 2, Al(NO 3 ) 3 a) Identify what type of electrolyte each compound is? b) How many moles of each ion are in an aqueous solution? Assume you start with one mole of each compound. c) What is the molarity of each ion in 0.500L of water?

7 Ex. 1) HCl, Ca(OH) 2, Al(NO 3 ) 3 a) Identify what type of electrolyte each compound is?

8 Ex. 1) HCl, Ca(OH) 2, Al(NO 3 ) 3 b) How many moles of each ion are in an aqueous solution? Assume you start with one mole of each compound.

9 Ex. 1) HCl, Ca(OH) 2, Al(NO 3 ) 3 c) What is the molarity of each ion in 0.500L of water?

10 Ex. 2) If ml of 0.100M HCl and ml of 0.100M NaOH are mixed, what is the molarity of the salt in the resulting soln? (Assume the volumes are additive)

11 Svante Augustus Arrhenius are anything that generate H + in aqueous solutions, while produce OH - in aqueous solutions HCl HCO 2 H H 2 O H 2 O H O 3 3 H O Cl - HCO - 2 NaOH Na OH aq aq -

12 Arrhenius Theory neutralization - combination of H + (or H 3 O + ) with OH - strong acids - ionize 100% in water strong bases - ionize 100% in water Neutralization can also happen with weak acids and/or weak bases (more on this coming soon) 12

13 Arrhenius Theory total ionic equation for strong acid with strong base - - H Cl Na OH Na Cl H2O aq aq aq aq aq aq (l) net ionic equation for strong acid with strong base 13

14 Bronsted-Lowry Acid Base Theory 2 nd definition - proton (H + ) donor HBr H O H O 2 3 Br - A B CA CB - proton (H + ) acceptor NH H O NH B A CA OH CB - 14

15 acid-base reactions are proton transfer reactions HCl A NH NH 3 4 B CA Cl CB note that we are often making bonds - between Arrhenius & Bronsted- Lowry theories reaction does not have to occur in an solution bases do not have to be ~ ammonia is not a hydroxide 15

16 Bronsted-Lowry Acid-Base Theory primary reason they are weak acids or bases: strong conjugates recombine to form the original species can be either an acid or base in Bronsted-Lowry theory It is both amphiprotic and amphoteric ~ can donate or accept a proton ~ a substance that can be either an acid or a base. 16

17 Amines are weak bases that behave like ammonia amines have organic groups attached to - NH 2 group NH CH 3 3 NH 2 H 2 O H 2 NH O 4 CH 3 OH NH 3 - OH - 17

18 Strengths of Acids - Binary Acids acid strength increases with decreasing bond strength (inversely proportional) Strongest bond = hydrogen halides bond strength acid strength HF>>HCl>HBr>HI 18

19 Strengths of Acids - VIA hydrides bond strength acid strength H 2 O>> H 2 S> H 2 Se> 19

20 Strengths of Acids strongest acid that can exist in water is H 3 O + acids that are stronger than H 3 O + merely react with water to produce H 3 O + consequently all strong soluble acids have the same strength in water can only distinguish acid strength differences of strong acids in solutions like acetic acid (weak acids)

21 Strengths of Acids in water is H 3 O + HCl + H 2 O H 3 O + + Cl - HCl is so strong it forces water to accept H + in water is OH - NH 2- + H 2 O NH 3 + OH - NH 2- is strong enough to remove H + from water Why? Water is 21

22 Strengths of Acids Acid Conjugate Base Strongest acid ~ Weakest base HClO 4 ClO - 4 H + (H 3 O + ) H 2 O CH 3 CO 2 H CH 3 CO - 2 H 2 O OH - NH 3 NH - 2 Weakest acid ~ Strongest base 22

23 Strengths of Acids ternary acids ternary acids, also known as oxyacids are acids containing H, O, and another element (usually a nonmetal) ternary acid strength usually increases with increasing number of O atoms on central atom increasing oxidation state of central atom acids having same central atom, of central atom is usually strongest acid HClO < HClO 2 < HClO 3 < HClO 4 HClO < HClO 2 < HClO 3 < HClO 4 Cl Cl Cl Cl 23

24 Strengths of Acids ternary acids weak ternary acids have stronger H-O bonds than stronger ternary acids acid strength HNO 2 <HNO 3 H 2 SO 3 < H 2 SO 4 H-O bond strength 24

25 Lewis Acid Base Theory 3 rd definition an electron pair acceptor an electron pair donor - coordinate covalent bond formation 25

26 Lewis Theory sodium fluoride + boron trifluoride but not Arrhenius or Bronsted-Lowry NaF + BF 3 Na + + BF - 4 ammonia + HBr but not Arrhenius NH 3 + HBr NH 4+ + Br - 26

27 Acidic, Basic, and Neutral Salts A is an ionic compound that contains at least one ion. The salt therefore completely in water (look at dissociation table) normal salts: contain no ionizible H atoms or OH groups. These salts have no effect on the ph of a solution. Normally formed between the reaction of a strong acid and strong base. Most alkali and alkaline earth binaries are neutral salts. Ex. NaCl, KI, LiNO 3, CaBr 2

28 Some salts will produce an acidic or basic solution when added to water. are ionic compounds that can provide an H + to a solution; does not necessarily produce acidic solns. These compounds are able to bases. Normally formed from the reaction of a strong acid and weak base. Ex. NH 4 I, KH 2 AsO 4, K 2 HPO 4, NaHSO 4, NaHCO 3 NH 4 I + H 2 O H 3 O + + NH 3 + I -

29 are ionic compounds that increase the OH - concentration. If the compound has an anion that would make a weak acid then it s a basic salt. Can contain unreacted OH group that can neutralize acids even though they are not necessarily basic. Most metal binary compounds in water make basic salts. Basic salts tend to be. Can also be formed from the reaction of a strong base and a weak acid. Ex. Al(OH) 2 Cl, Fe(OH) 2 and some anions to look for F -, CN -, CNS -, H - NaF + H 2 O Na + + OH - + HF Li 2 C 2 O 4 + H 2 O H 2 C 2 O 4 + Li + + OH -

30 Ex. 3) a) If 100.0mL of 0.100M HCl and ml of M NaOH are mixed, what are the molarities of the solutes in the resulting soln? b) What is the ph? (Remember: HCl, NaOH, and NaCl are strong electrolytes)

31 Ex. 4) What volume of M HCl soln would neutralize 30.0 ml of M Ca(OH) 2

32 Ex. 5) a) Find the molarity of 37.7 ml of H 2 SO 4 when it is titrated with 42.2 ml of 0.236M NaOH. b) What is the ph of the acid?

33 Ex. 6) A ml sample of 0.275M lithium hydroxide completely reacts with ml of phosphoric acid. What is the molarity of the acidic solution?

34 Ex. 7) if [OH - ] = 7.2 x 10-6 M what is the ph?

35 Ex. 8) when ph = what is [H 3 O + ]?

36 Ex. 9) [H 3 O + ]= x 10-4 M, poh =?

37 Ex. 10) [HNO 3 ] = 2.4 M, what is the ph?

38 Ex. 11) [H 2 SO 4 ] = M, what is the ph?

39 Ex. 12) ph =? When [Sr(OH) 2 ] = 1.55 x 10-3 M

40 Ex. 13) Calculate the concentrations of H 3 O + and OH - in M HCl and find the ph of the solution. HCl + H 2 O H 3 O + Cl 40

41 Ex. 14) Calculate [H 3 O + ], ph, [OH - ], and poh for M Ba(OH) 2 solution. 41

42 Ex. 15) a) How many ml of concentrated 12 M HCl will you need to make L of M HCl? b) What is the initial ph? c) What is the resulting ph?

43 Ex. 16) You add 500. ml of water to 500. ml of 1.25 M NaOH. What is the ph of the resulting solution?

44 Ex. 17) A g sample of an impure Iron(II) sulfate is titrated with ml of M potassium permangante in an acidified solution to the endpoint. What is the % purity of the ferrous sulfate?

45 A. One method of increasing the solubility and the absorption of a medication is to convert weakly acidic drugs into sodium salts before making the pills that will be ingested. How does this preparation method enhance the drug s solubility in the stomach? (hint: stomach acid is about 1M HCl) B. Medicines that are weakly basic are not absorbed well into the bloodstream. One method to increase their absorption is to take an antacid at the same time that the medicine is administered. How does this method increase the absorption?