Equations

M = n/V

M1V1 = M2 V2 if the moles are the same

n1 n2 you can cancel out the n’s.

pH = -log [H+ ] pOH = -log [OH- ]

pH + pOH = 14

[H3O+] = 10^-pH [OH-] = 10^-pOH

[H3O+] [OH-] = 1.0 x 10-14

3

Strong Electrolytes

Strong electrolytes ___________ or

___________ completely

Three classes of strong electrolytes

1. ___________ ___________

2. ___________ ___________

3. ___________ ___________

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 ___________

Properties of Bases

• taste ___________

• feel ___________

• change colors of indicators

• turn litmus paper blue

• react with ___________ to form salts

and water

• aqueous solutions conduct electricity

Ex. 1) HCl, Ca(OH)2, Al(NO3)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?

Ex. 1) HCl, Ca(OH)2, Al(NO3)3

a) Identify what type of electrolyte each compound

is?

Ex. 1) HCl, Ca(OH)2, Al(NO3)3

b) How many moles of each ion are in an aqueous

solution? Assume you start with one mole of

each compound.

Ex. 1) HCl, Ca(OH)2, Al(NO3)3

c) What is the molarity of each ion in 0.500L of

water?

Ex. 2) If 200.0 mL of 0.100M HCl and 200.0 mL of

0.100M NaOH are mixed, what is the molarity of

the salt in the resulting soln? (Assume the

volumes are additive)

Svante Augustus Arrhenius - 1884

___________ are anything that generate H+ in aqueous solutions, while ___________ produce OH- in aqueous solutions

-

2322

-

32

HCO O H O HH HCO

Cl O H O H HCl

-

aqaq OH Na NaOH

Arrhenius Theory neutralization - combination of H+ (or H3O

+)

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

(l)O HCl Na OH Na Cl H 2-

aqaq

-

aqaqaqaq

net ionic equation for strong acid with

strong base

14

Bronsted-Lowry Acid Base Theory

2nd definition ___________ - proton (H+) donor

___________ - proton (H+) acceptor

CB CA B A

Br OH OH HBr -32

CB CA A B

OH NH OH NH -423

15

acid-base reactions are proton transfer reactions

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

CB CA B A

Cl NH NH HCl -43

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.

17

Amines

___________ are weak bases that behave

like ammonia

amines have organic groups attached to -

NH2 group

-

33223

-

423

OH NHCH O H NHCH

OH NH O H NH

18

Strengths of Acids - Binary Acids

acid strength increases with decreasing

bond strength (inversely proportional)

Strongest bond = ___________ ________

hydrogen halides

bond strength

HF>>HCl>HBr>HI

acid strength

19

Strengths of Acids - VIA hydrides

bond strength

H2O>> H2S> H2Se>

acid strength

Strengths of Acids

___________

strongest acid that can exist in water is

H3O+

acids that are stronger than H3O+ merely

react with water to produce H3O+

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 H3O+

HCl + H2O H3O+ + Cl-

HCl is so strong it forces water to accept H+

___________ ___________ in water is OH-

NH2- + H2O NH3 + OH

-

NH2- is strong enough to remove H+ from water

Why? Water is ___________

22

Strengths of Acids

Acid Conjugate Base

Strongest acid ~ Weakest base

HClO4 ClO4-

H+ (H3O+) H2O

CH3CO2H CH3CO2-

H2O OH-

NH3 NH2-

Weakest acid ~ Strongest base

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 < HClO2 < HClO3 < HClO4

HClO < HClO2 < HClO3 < HClO4Cl Cl Cl Cl

24

Strengths of Acids – ternary acids

weak ternary acids have stronger H-O

bonds than stronger ternary acids

acid strength

HNO2

25

Lewis Acid Base Theory

3rd definition

___________ – an electron pair acceptor

___________ – an electron pair donor

___________ - coordinate covalent bond

formation

26

Lewis Theory

sodium fluoride + boron trifluoride

___________ ___________ but not Arrhenius or Bronsted-Lowry

NaF + BF3 Na+ + BF4

-

ammonia + HBr

___________ ___________ ___________ ______ but not Arrhenius

NH3 + HBr NH4+ + Br-

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, LiNO3, CaBr2

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. NH4I , KH2 AsO4, K2 HPO4, NaHSO4 , NaHCO3

NH4 I + H2O H3O+ + NH3 + I

-

___________ ___________ 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 + H2O Na+ + OH- + HF

Li2C2O4 + H2O H2C2O4 + Li+ + OH-

Ex. 3)

a) If 100.0mL of 0.100M HCl and 100.0 mL of

0.0875M 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)

Ex. 4) What volume of 0.00350M HCl soln would

neutralize 30.0 mL of 0.00100M Ca(OH)2

Ex. 5)

a) Find the molarity of 37.7 mL of H2SO4 when it is

titrated with 42.2 mL of 0.236M NaOH.

b) What is the pH of the acid?

Ex. 6) A 150.0 mL sample of 0.275M lithium

hydroxide completely reacts with 294.3 mL of

phosphoric acid. What is the molarity of the

acidic solution?

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

Ex. 8) when pH = 7.706 what is [H3O+]?

Ex. 9) [H3O+]= 1.120 x 10-4 M, pOH = ?

Ex. 10) [HNO3] = 2.4 M, what is the pH?

Ex. 11) [H2SO4] = 0.444 M, what is the pH?

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

40

Ex. 13) Calculate the concentrations of H3O+ and

OH- in 0.050 M HCl and find the pH of the solution. Cl OH OH + HCl +32

41

Ex. 14) Calculate [H3O+], pH, [OH-], and pOH for

0.020 M Ba(OH)2 solution.

Ex. 15)

a) How many mL of concentrated 12 M HCl will

you need to make 0.500 L of 0.750 M HCl?

b) What is the initial pH?

c) What is the resulting pH?

Ex. 16) You add 500. mL of water to 500. mL of

1.25 M NaOH. What is the pH of the resulting

solution?

Ex. 17) A 0.750 g sample of an impure Iron(II)

sulfate is titrated with 26.25 mL of 0.0200M

potassium permangante in an acidified solution

to the endpoint. What is the % purity of the

ferrous sulfate?

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?