Notes 

Chem. Chapter 16 (p.556-595)

Read page 593

Acidic solution=

Contain more Hydrogen ions[H+1]  than Hydroxide ions[OH-1].

Basic Solution=

Contain more Hydroxide ions [OH-1] than Hydrogen ions[H+1].

Neutral Solution=

Contain equal amounts of Hydroxide ions [OH-1] and Hydrogen ions[H+1].

Group question-Classifications of acids and bases.

Conjugate Acid=

Generally a weak acid formed as a strong base accepted a hydrogen ion or proton.

Conjugate base=

Generally a weak base formed as a strong acid donates a hydrogen ion or proton.

Ex.

HCl(aq) + NaOH(aq) à  H2O(l) + NaCl(aq) Balanced

                                 H-OH

Acid          Base               Conjugate  Conjugate

                                 Acid           Base

Things to remember

·                     Acids away- Acids give away  H’s.

·                     Bases bring-Bases bring in H’s.

·                     Acids and bases are always on the reactant side.

·                     Conjugate Acid and Conjugate Base are always on the product side.

Conjugate Acid-Base Pair=

Consists of two substances related to each other by the donating and accepting of a single hydrogen ion.

Amphoteric substances=

A substance that can act either as an acid or base.

Example is water.

Monoprotic Acids= 

Acids with only one Hydrogen or proton.

Diprotic Acids= 

Acids with two Hydrogens or protons.

Triprotic Acids= 

Acids with three Hydrogens or protons.

*Oxyacids=

Acids in which the acidic hydrogen is attached to an oxygen atom.(Usually strong acids.)

*Organic acids=

Acids with a Carbon backbone.

                                 O

                                   ||

Carbonyl= The –C-OH group.

Anhydrides=

Molecules that lack water.  *These molecules can react with water in the air and form acids.

Strong Acids=

 Acids that completely ionize or dissociate. (The ions separate.)

Weak Acids=

Acids that do not completely ionize or dissociate.

Acid ionization constant=Ka=

The value of the equilibrium constant expression for the ionization of a weak acid. (The number that indicates if the products or reactants are favored.)

Strong Bases=

 Bases that completely ionize or dissociate. (The ions separate.)

Weak Bases =

Bases that do not completely ionize or dissociate.

Bases ionization constant=Kb=

The value of the equilibrium constant expression for the ionization of a weak base. (The number that indicates if the products or reactants are favored.)

Ionization of water=

A process in which the protons of one molecule of water are transferred to another. .(Water forms ions)

H2O à H+1 + OH-1

Kw= The Ion-Product constant of water.

Kw= [OH-1] [H+1]= 1 X 10-14

LeChatelier’s Principle=

The concentration of [OH-1] and [H+1] will adjust based on the outside pressures place on the mixture.

Talk about the difference on the pH scale.

pH = Potential Hydrogen =

Measurement of Hydrogen in a substance.

pH=-log [H+1]

[H3O+1] = [H+1] =

Hydronium ion concentration.

pOH =Potential Hydroxide=

Measurement of Hydroxide in a substance.

[OH-1] =

Hydroxide ion concentration.

pOH=-log [OH-1]

pH + pOH =14

 [H+1] [OH-1] = 1 X 10-14

pOH =-log[OH-1]

[OH-1] = 1 X 10-pOH

pH =-log[H+1]

[H+1] = 1 X 10-pH

Problems-

Calculate the pH, pOH, [H+]and [OH-]  Also, indicate if the sample is Acid, Base or Neutral.

Ex. pOH = 2

pH + pOH =14   therefore pH=14 - pOH

pH = 14-2=12

[H+] = inverse log of 12 = 1 X 10-12.

[OH-]= inverse log of 2 = 1 X 10-2

pH is more than 7, so it is a base.

*pH scale=

A range of numbers that indicate the concentration of the Hydronium ion in the substance.

The three divisions of the pH scale are:

Acids= Less than 7 on the pH scale. (Have a sour taste.)

*acid-a substance that produces hydrogen ions (H+1) in solution.

Bases=More than 7 on the pH scale. (Have a bitter taste.) (Feel slippery-fish)

*base- substances that produces hydroxide ions (OH-) in solution.

Neutral= Equal to 7 on the pH scale.

The hydroxide ions (OH-) and hydrogen ions (H+1) are equal.

*hydronium ion-ion formed by bonding a hydrogen ion (H+1), to a water molecule to give H3O+1.

pH + pOH =14

[OH-1] [H+1]= 1 X 10-14

Indicator paper(pH paper)=

A strip of paper that has been coated with a combination of indicators, and they change to different colors at different pH levels.

pH meter=

A device that measures the pH value electronically.

Neutralization rx-

A process in which acids are added to bases or vice versa to get the pH to 7.

(This process produces salt water.)

Salt= A compound produced in a neutralization reaction. (Usually made of a metal and a nonmetal.)

Titration-

A process in which a known concentration of a base is added to an unknown concentration, or known volume of an acid to determine the concentration of the unknown. (Or vice versa.){A process of neutralization.}

Titration problems-Example

i.e. What is the concentration if 50 ml of 2 m base is added to 100 ml of acid?

Concentration of acid(volume of acid)= Concentration of base(volume of base) CAVA=CBVB

(CA) 100 ml = 2 m(50ml)

(CA) 100 ml = 2 m(50ml)

     100 ml    100 ml                                                                               

CA= 1 m

Titrant=

The acid/base with the known concentration.

*Standard solution=

The acid/base with the known concentration.

*Analyte=

The acid/base with the unknown concentration.

Equivalent point (stoichiometric point)=

This results when the substances are neutralized in the titration reaction.

*Titration curve (pH curve)=

A plot of the results of a neutralization reaction. (p. 661)

Acid-Base Indicators=

Substances that change color as the pH of the sample changes.

End point=

The point at which the indicator used will show a drastic change.

Salt hydrolysis=

The anions of the dissociated salt accepts the hydrogen ions from the water or the cations of the dissociated salt accepts the hydroxide ions of the water.(A process in which water breaks apart and the H+ combines with the anion and the OH- combines with the cation.)

Buffered solution=

This is a mixture that resists change to the pH even when strong acids and bases are added.

(They usually contain weak acids and their conjugate base.)

Buffer capacity=

The maximum amount of acid or base a solution can absorb without significant change in pH.

*Acid precipitation=

Any form of precipitation having a pH lower than 5.6.

pH in the blood

*Acidosis=

A harmful condition in which the pH of the blood stays below 7.35.

Mild cases result in mental confusion and/or disorientation.

Extreme cases shock, coma, or death.

*Alkalosis=

A harmful condition in which the pH of the blood stays above 7.40.

Temporary alkalosis results in vomiting.

Chronic alkalosis can produce weak breathing and muscle contractions.

Severe alkalosis can lead to convulsion and death.

Models of Acid/Base pairs

A) Arrhenius model

Acid- These produce H+ ions in water.

Base- These produce OH- ions in water.

B) Bronsted-Lowry model

Acid- These are proton/Hydrogen donors.(Give Hydrogens Away.)

Base- These are proton/Hydrogen acceptors.(Bring in Hydrogens.)

C) Lewis model

Acid- These are electron acceptors.

Base-These are electron donors.