Chapter #14 Acids, Bases, and Salts.

Chapter #14 Acids, Bases, and Salts

Acids, Bases and Salts Topics
The Arrhenius Theory The Brønsted Theory Naming Acids (See Nomenclature Notes) The Self-Ionization of Water The pH Concept Properties of Acids Properties of Bases Salts The Strengths of Acids and Bases Analyzing Acids and Bases Titration Calculations Hydrolysis Reactions of Salts Buffers

History of Acids and Bases
In the early days of chemistry chemists were organizing physical and chemical properties of substances. They discovered that many substances could be placed in two different property categories: Substance A Sour taste Reacts with carbonates to make CO2 Reacts with metals to produce H2 Turns blue litmus pink Reacts with B substances to make salt water Substance B Bitter taste Reacts with fats to make soaps Do not react with metals Turns red litmus blue Reacts with A substances make salt and water Arrhenius was the first person to suggest a reason why substances are in A or B due to their ionization in water.

Arrhenius Theory The Swedish chemist Svante Arrhenius proposed the first definition of acids and bases. (Substances A and B became known as acids and bases) According to the Arrhenius model: “acids are substances that dissociate in water to produce H+ ions and bases are substances that dissociate in water to produce OH- ions” NaOH (aq)  Na+ (aq) OH- (aq) Base HCl (aq)  H+ (aq) Cl- (aq) Acid

What is H+? e- + + Proton (H+) Hydrogen (H)

Hydronium Ion Unknown to Arrhenius free H+ ions do not exist in water. They covalently react with water to produce hydronium ions, H3O+. or: H+ (aq) H2O (l)  H3O+ (aq) This new bond is called a coordinate covalent bond since both new bonding electrons come from the same atom

Hydronium Ion Hydronium ion is the name for H3O+ and is often times abbreviated as H+ (aq) they both mean the same thing. What is the difference between a strong acid and a weak acid?

Hydronium Ion Hydronium ion is the name for H3O+ and is often times abbreviated as H+ (aq) they both mean the same thing. What is the difference between a strong acid and a weak acid? Strong acids ionize 100% and weak ones do not!

Hydronium Ion Hydronium ion is the name for H3O+ and is often times abbreviated as H+ (aq) they both mean the same thing. What is the difference between a strong acid and a weak acid? Strong acids ionize 100% and weak ones do not! A single arrow is used to represent the ionization of a strong acid. Double arrows (Equilibrium) are used to represent weak acids. For example: HCl (g) H+ (aq) + Cl - (aq) HF (g) H+ (aq) + F -

HOH (l) H+ (aq) + OH – (aq)
Hydronium Ion Hydronium ion is the name for H3O+ and is often times abbreviated as H+ (aq) they both mean the same thing. What is the difference between a strong acid and a weak acid? Strong acids ionize 100% and weak ones do not! A single arrow is used to represent the ionization of a strong acid. Double arrows (Equilibrium) are used to represent weak acids. For example: HCl (g) H+ (aq) + Cl - (aq) HF (g) H+ (aq) + F - According to Arrhenius, is water an acid or base? HOH (l) H+ (aq) + OH – (aq)

HOH (l) H+ (aq) + OH – (aq)
Hydronium Ion Hydronium ion is the name for H3O+ and is often times abbreviated as H+ (aq) they both mean the same thing. What is the difference between a strong acid and a weak acid? Strong acids ionize 100% and weak ones do not! A single arrow is used to represent the ionization of a strong acid. Double arrows (Equilibrium) are used to represent weak acids. For example: HCl (g) H+ (aq) + Cl - (aq) HF (g) H+ (aq) + F - According to Arrhenius, is water an acid or base? HOH (l) H+ (aq) + OH – (aq) Neither, he called it Neutral (same amount of OH- and H+

Strong Acids and Bases How can we identify strong acids or bases?

How can we identify strong acids or bases? Easy memorize them!
Strong Acids and Bases How can we identify strong acids or bases? Easy memorize them!

How can we identify strong acids or bases? Easy, memorize them!
Strong Acids and Bases How can we identify strong acids or bases? Easy, memorize them! Memorized Strong Acids HClO4 H2SO4 HI HBr HCl HNO3 Memorized Strong Bases Hydroxides of group 1 and 2 metals, excluding Be and Mg

HCl (aq) + H2O (l)  Cl- (aq) + H3O+ (aq)
Bronsted Lowry Theory Johannes Brønsted and Thomas Lowry revised Arrhenius’s acid-base theory to include this behavior. They defined acids and bases as follows: “An acid is a hydrogen containing species that donates a proton. A base is any substance that accepts a proton” HCl (aq) H2O (l)  Cl- (aq) H3O+ (aq) In the above example what is the Brønsted acid? What is the Brønsted base? Bronsted Lowry

Bronsted Lowry Theory In reality, the reaction of HCl with H2O is an equilibrium and occurs in both directions, although in this case the equilibrium lies far to the right. HCl (aq) H2O (l)  Cl - ( aq) H3O+ (aq) For the reverse reaction Cl - behaves as a Brønsted base and H3O+ behaves as a Brønsted acid. The Cl- is called the conjugate base of HCl. Brønsted acids and bases always exist as conjugate acid-base pairs.

Autoionization of Water
In pure water (no solute) water molecules behave as both an acid and base!! e.g. H2O (l) + H2O (l)  H3O+ (aq) OH- (aq) This is called the self-ionization (autoionizaion) of water. Although the equilibrium lies far to the left it is very important to take into consideration, especially for living systems. Does anyone know how we write the equilibrium constant for this reaction?

The auto-ionization of water is described by the equation: H2O (l) + H2O (l)  H3O+ (aq) OH- (aq) The equilibrium constant for this reaction is given by: Kw = K[H2O]2 = This equilibrium lies very much to the left i.e. mostly water. For pure water [OH-] = [H+] = 1 x 10-7 M

As [OH-] and [H+] are so small the [H2O] is not affected by their formation. It is useful to define a new constant Kw such that: 1.00 g mole ml = 55.5 M ml 18.0 g 10-3 L Kw is called the ion product of water. What is the value for the ion product of water?

As [OH-] and [H+] are so small the [H2O] is not affected by their formation. It is useful to define a new constant Kw such that: 1.00 g mole ml = 55.5 M ml 18.0 g 10-3 L Kw is called the ion product of water. What is the value for the ion product of water? [H+][OH-] = 10-14

We define an aqueous solution as being neutral when the [H+] = [OH-]. We define an aqueous solution as being acidic when [H+] > [OH-]. We define an aqueous solution as being basic when [H+] < [OH-]. However, in each case Kw = 1 x M2 [H+] = = (how can this be abbreviated further?)

We define an aqueous solution as being neutral when the [H+] = [OH-]. We define an aqueous solution as being acidic when [H+] > [OH-]. We define an aqueous solution as being basic when [H+] < [OH-]. However, in each case Kw = 1 x M2 [H+] = = (how can this be abbreviated further?) By just describing the power

We define an aqueous solution as being neutral when the [H+] = [OH-]. We define an aqueous solution as being acidic when [H+] > [OH-]. We define an aqueous solution as being basic when [H+] < [OH-]. However, in each case Kw = 1 x M2 [H+] = = (how can this be abbreviated further?) By just describing the power Called the power of H, or pH.

We define an aqueous solution as being neutral when the [H+] = [OH-]. We define an aqueous solution as being acidic when [H+] > [OH-]. We define an aqueous solution as being basic when [H+] < [OH-]. However, in each case Kw = 1 x M2 [H+] = = (how can this be abbreviated further?) By just describing the power Called the power of H, or pH. Our math departments tells us that log means power too. pH = 7

The mathematical definition of pH using [H+] for [H3O+] is listed below:
pH = -log [H+], or [H+]= 1x10-pH (both are mathematically equivalent) How about the power for the OH -, what should this be called?

The mathematical definition of pH using [H+] for [H3O+] is listed below: pH = -log [H+], or [H+] = 1x10-pH (both are mathematically equivalent) How about the power for the OH -, what should this be called? Would you believe pOH?

The mathematical definition of pH using [H+] for [H3O+] is listed below: pH = -log [H+], or [H+]= 1x10-pH (both are mathematically equivalent) How about the power for the OH -, what should this be called? Would you believe pOH? Have you heard of pOH before?

The mathematical definition of pH using [H+] for [H3O+] is listed below: pH = -log [H+], or [H+]= 1x10-pH (both are mathematically equivalent) How about the power for the OH -, what should this be called? Would you believe pOH? Have you heard of pOH before? pH + pOH = 14 for water solutions.

Now for some examples Find the pH and pOH, when [H+] = 10-4

Now for some examples Find the pH and pOH, when [H+] = 10-4
pH = 4 and pOH = 10, since they must add to 14 using the calculator pH = -log [H+], type in 10-4, push the log button and pH = -(-4) = 4. Same for pOH

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 pH = 12 pH = 7 [H+] = 10-2 pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 pH = 12 pH = 7 [H+] = 10-2 [OH -] = 10-12 pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 pH = 12 pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 pH = 12 [H+] = 10-7 [OH -] = 10-7 pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 pH = 12 [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 [H+] =10-12 [OH -] = 10-2 pH = 12 [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. pH = 16 [H+] =10-12 [OH -] = 10-2 pH = 12 [H+] < [OH -] basic [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. [H+] =10-16 [OH -] = pH = 16 [H+] =10-12 [OH -] = 10-2 pH = 12 [H+] < [OH -] basic [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. [H+] =10-16 [OH -] = 102 pH = 16 [H+] =10-12 [OH -] = 10-2 pH = 12 [H+] < [OH -] basic [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. [H+] =10-1 [OH -] = 102 [H+] < [OH -] basic pH = 16 [H+] =10-12 [OH -] = 10-2 pH = 12 [H+] < [OH -] basic [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. [H+] =10-16 [OH -] = 102 [H+] < [OH -] basic pH = 16 [H+] =10-12 [OH -] = 10-2 pH = 12 [H+] < [OH -] basic [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 acidic [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

A pH Number line Number lines have been used in history and math classes, so to keep up we use them in chemistry classes. [H+] =10-16 [OH -] = 102 [H+] < [OH -] basic pH = 16 [H+] =10-12 [OH -] = 10-2 basic pH = 12 [H+] < [OH -] basic [H+] = 10-7 [OH -] = 10-7 [H+] = [OH -] neutral pH = 7 acidic [H+] = 10-2 [OH -] = 10-12 [H+] > [OH -] acidic pH = 2

Equations With Acuids Acids undergo characteristic double replacement reactions with oxides, hydroxides, carbonates and bicarbonates. e.g. 2HCl (aq) CuO (s)  CuCl2 (aq) H2O (l) 2HCl (aq) Ca(OH)2 (aq)  CaCl2 (aq) H2O (l) 2HCl (aq) CaCO3 (aq)  CaCl2 (aq) H2O (l) CO2 (g) 2HC l (aq) + Sr(HCO3)2 (aq)  SrCl2 (aq) + 2H2O (l) CO2 (g)

Equations With Acuids Bases undergo a double replacement reaction with acids called neutralization: NaOH (aq) HCl (aq)  H2O (l) NaC l (aq) In words this well known reaction is often described as: “acid plus base = salt plus water” We previously discussed this reaction when describing types of reactions.

Ionic Equations (a review)
We have discussed the double replacement reactions and ionic equations before. Since the acids and bases undergo double replacement reactions called neutralization reactions, then they can have ionic equations too. e.g. Formula equation: HCl (aq) NaOH (aq)  NaCl (aq) H2O (l) Ionic equation: H+ (aq) + Cl- (aq) + Na+ (aq) + OH- (aq)  Na+ (aq) + Cl- (aq) + H2O (l) Net ionic equation: H+ (aq) OH- (aq)  H2O (l)

Acidic Single Replacement Reactions
Another property of acids is their reaction with certain metals to produce hydrogen gas, H2 (g). Zn (s) HC l (aq)  H2 (g) ZnCl2 (aq) This is an example of a single replacement reaction and is a redox reaction. Total ionic equation: Zn (s) H+ (aq) Cl- (aq)  H2 (g) Zn2+ (aq) Cl- (aq) Net ionic equation: Zn (s) H+ (aq)  H2 (g) Zn2+ (aq)

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl Reactants are? NaCl + HOH

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH S.A. s.b. NaC2H3O2 + HOH

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt S.A. s.b. NaC2H3O2 + HOH

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH w.a. s.b.

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH basic salt w.a. s.b.

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH basic salt w.a. s.b. NH4Cl + HOH

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH basic salt w.a. s.b. NH4OH NH4Cl + HOH HCl +

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH Neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH basic salt w.a. s.b. HCl + NH4OH NH4Cl + HOH s.a. w.b.

Salts Salts are the ionic product of an acid base neutralization reaction. Acidic Salts are formed from a strong acid and a weak base. Neutral salts are formed from a strong acid and strong base. Basic salts are formed from a strong base and a weak acid. Give the acid and base the following salts were formed from and label the salts as acidic, basic, or neutral. NaCl NaC2H3O2 NH4Cl HCl + NaOH NaCl + HOH neutral salt s.a. s.b. HC2H3O2 + NaOH NaC2H3O2 + HOH basic salt w.a. s.b. HCl + NH4OH NH4Cl + HOH acidic salt s.a. w.b.

Acid, Base, and Salt Hydrolysis
HBr (aq)

HBr (aq) H+ (aq) Br - (aq)

HBr (aq) H+ (aq) Br - (aq) Acidic, because H+ (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq)

0.1 0.0 Initial concentration HBr (aq) H+ (aq) Br - (aq)

0.1 0.0 ? Initial concentration HBr (aq) H+ (aq) Br - (aq)

0.1 0.0 0.0 Initial concentration HBr (aq) H+ (aq) Br - (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) ? Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 ? Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 ? Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 0.1 Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 0.1 Final concentration [H+] = ?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 0.1 Final concentration [H+] = 0.1

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 0.1 Final concentration [H+] = 0.1 pH = ?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 0.1 Final concentration [H+] = 0.1 = 10-1 pH = ?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) 0.0 0.1 0.1 Final concentration [H+] = 0.1 = 10-1 pH = 1

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) acidic?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration Ca2+ (aq) OH- (aq) No, basic OH- Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 ? Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) ? Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 ? Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 ? Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = ?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2 pOH = ?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2 pOH = - log[OH-]

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2 pOH = - log[OH-] = - log[0.2]

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2 pOH = - log[OH-] = - log[0.2] = -( ) pOH = 0.7

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2 pOH = - log[OH-] = - log[0.2] = -( ) pOH = 0.7 pH = ?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) 0.0 0.1 0.2 Final concentration [OH - ] = 0.2 pOH = - log[OH-] = - log[0.2] = -( ) pOH = 0.7 pH = = 13.3

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration NaF (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration NaF (aq) Na+ (aq) + F – (aq)

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration NaF (aq) Na+ (aq) + F – (aq) Acidic, basic, or neutral?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration Basic, since HF is w.a. and NaOH is s.b. NaF (aq) Na+ (aq) + F – (aq) Will sodium and fluorine ions react with water?

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration Basic, since HF is w.a. and NaOH is s.b. NaF (aq) Na+ (aq) + F – (aq) Will sodium and fluorine ions react with water? Na+ + HOH NaOH (sb) + H+

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration Basic, since HF is w.a. and NaOH is s.b. NaF (aq) Na+ (aq) + F – (aq) Will sodium and fluorine ions react with water? Na+ + HOH NaOH (sb) + H+ Na+ + HOH Na+ + OH H+ No Reaction, water cannot make water HOH OH- + H+

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration Basic, since HF is w.a. and NaOH is s.b. NaF (aq) Na+ (aq) + F – (aq) Will sodium and fluorine ions react with water? Cannot make strong acids or bases from weak ones Na+ + HOH NaOH + H+ s.b.

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration Basic, since HF is w.a. and NaOH is s.b. NaF (aq) Na+ (aq) + F – (aq) Will sodium and fluorine ions react with water? Cannot make strong acids or bases from weak ones Na+ + HOH NaOH + H+ F HOH HF + OH- w.a.

0.1 Initial concentration HBr (aq) H+ (aq) Br - (aq) pH = 1 0.0 0.1 0.1 Final concentration 0.1 0.0 0.0 Initial concentration Ca2+ (aq) OH- (aq) Ca(OH)2 (aq) pH = 13.3 0.0 0.1 0.2 final concentration Basic, since HF is w.a. and NaOH is s.b. NaF (aq) Na+ (aq) + F – (aq) Will sodium and fluorine ions react with water? Cannot make strong acids or bases from weak ones Na+ + HOH NaOH + H+ F HOH HF + OH- Yes, HF weak acid and OH- is formed, thus basic salt! w.a.

NH4Cl (aq) NH4+ (aq) + Cl- (aq)

NH4Cl (aq) NH4+ (aq) + Cl- (aq) acidic, basic, or neutral?

HCl + NH4OH NH4Cl + HOH NH4Cl (aq) NH4+ (aq) + Cl- (aq) acidic, basic, or neutral?

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) acidic, basic, or neutral?

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? NH HOH NH4OH + H+

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? NH HOH NH4OH + H+ w.b.

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b.

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Cl- + HOH HCl + OH-

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Cl- + HOH HCl (sa) + OH-

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Cl- + HOH H+ + Cl OH-

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Again water cannot make water! NR H+ + OH- HOH

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Cl- + HOH HCl + OH- s.a.

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Cannot form s.a. from weaker reactants, thus N.R. Cl- + HOH HCl + OH- s.a.

HCl + NH4OH NH4Cl + HOH s.a. w.b. NH4Cl (aq) NH4+ (aq) + Cl- (aq) Acidic! Will the ions from the salt combine with water? This reaction is OK, since a w.b. is formed NH HOH NH4OH + H+ w.b. Cannot form s.a. from weaker reactants, thus N.R. Cl- + HOH HCl + OH- s.a. Since H+ was formed in the first reaction, then [H+] is now greater than [OH-] making the solution acidic

NaCl (aq)

Na+ (aq) Cl- (aq) NaCl (aq)

Na+ (aq) Cl- (aq) NaCl (aq) Acidic, basic, or neutral?

HCl NaOH NaCl HOH Na+ (aq) Cl- (aq) NaCl (aq) Acidic, basic, or neutral?

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Acidic, basic, or neutral?

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral!

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral! Now react each of the ions with water. Na HOH NaOH + H+

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral! Now react each of the ions with water. Na HOH NaOH + H+ s.b.

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral! Now react each of the ions with water. Cannot form strong bases from weaker ones, thus N.R. Na HOH NaOH + H+ s.b.

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral! Now react each of the ions with water. Cannot form strong bases from weaker ones, thus N.R. Na HOH NaOH + H+ s.b. Cl HOH HCl OH-

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral! Now react each of the ions with water. Cannot form strong bases from weaker ones, thus N.R. Na HOH NaOH + H+ s.b. Cl HOH HCl OH- s.a.

HCl NaOH NaCl HOH s.a. s.b. Na+ (aq) Cl- (aq) NaCl (aq) Neutral! Now react each of the ions with water. Cannot form strong bases from weaker ones, thus N.R. Na HOH NaOH + H+ s.b. Cannot form strong acids from weaker ones, thus N.R. Cl HOH HCl OH- s.a.

Buffers Buffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions.

Buffers Buffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions. Our blood must maintain a pH around If the pH is above 7.45 you would have a condition called alkalosis. If the pH is below 7.35, then one would suffer from acidosis.

Buffers Buffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions. Our blood must maintain a pH around If the pH is above 7.45 you would have a condition called alkalosis. If the pH is below 7.35, then one would suffer from acidosis. Acidosis leads to depression of the nervous system. Mild acidosis can result in dizziness, disorientation, or fainting; a more severe case can cause coma, or death.

Buffers Buffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions. Our blood must maintain a pH around If the pH is above 7.45 you would have a condition called alkalosis. If the pH is below 7.35, then one would suffer from acidosis. Acidosis leads to depression of the nervous system. Mild acidosis can result in dizziness, disorientation, or fainting; a more severe case can cause coma, or death. What would happen to the pH of our blood if we were to eat acidic foods, such as apples, oranges, or limes? What might happen to the pH of our blood if some of the hydrochloric acid from our stomach were to seep into our blood?

Buffers Buffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions. Our blood must maintain a pH around If the pH is above 7.45 you would have a condition called alkalosis. If the pH is below 7.35, then one would suffer from acidosis. Acidosis leads to depression of the nervous system. Mild acidosis can result in dizziness, disorientation, or fainting; a more severe case can cause coma, or death. What would happen to the pH of our blood if we were to eat acidic foods, such as apples, oranges, or limes? What might happen to the pH of our blood if some of the hydrochloric acid from our stomach were to seep into our blood? The pH would be lower in both

What is a buffer and how does it work?
Despite the possibility of pH increases or decreases, the body maintains a nearly constant pH of The body uses buffers to maintain this remarkable feat. What is a buffer and how does it work?

Despite the possibility of pH increases or decreases, the body maintains a nearly constant pH of The body uses buffers to maintain this remarkable feat. What is a buffer and how does it work? A buffer consists of a weak acid and the salt of its conjugate base, or a weak base and the salt of its conjugate acid. Examples: HF + NaOH NaF + HOH w.a. c.b.

Despite the possibility of pH increases or decreases, the body maintains a nearly constant pH of The body uses buffers to maintain this remarkable feat. What is a buffer and how does it work? A buffer consists of a weak acid and the salt of its conjugate base, or a weak base and the salt of its conjugate acid. Examples: HF + NaOH NaF + HOH w.a. c.b. NH3 + HCl NH4Cl w.b. c.a.

HF (g) NaF (s) Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. 1.0 L

HF (g) NaF (s) Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. H+ Na+ F- HF HF (g)  H+ + F- 1.0 L large small NaF (s) Na+ + F-

Now add the strong acid HCl
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. HF H+ Na+ F- HF (g)  H+ + F- 1.0 L large small NaF (s) Na+ + F- Now add the strong acid HCl

Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. HF H+ Na+ F- HF (g)  H+ + F- 1.0 L small Large Cl- H+ NaF (s) Na+ + F- Now add the strong acid HCl What will the pH be if just water and no buffer? HCl H+ + Cl-

Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. H+ HF Na+ F- HF (g)  H+ + F- 1.0 L small Large Cl- H+ NaF (s) Na+ + F- Now add the strong acid HCl What will the pH be if just water and no buffer? pH = 1, dead if this is your blood. HCl H+ + Cl-

Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. H+ HF Na+ F- HF (g)  H+ + F- 1.0 L small Large Cl- H+ NaF (s) Na+ + F- Now add the strong acid HCl What will the pH be if just water and no buffer? pH = 1, dead if this is your blood. HCl H+ + Cl- What removes the H+ to keep the pH near 7?

Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. H+ HF Na+ F- HF (g)  H+ + F- 1.0 L small Large Cl- H+ NaF (s) Na+ + F- Now add the strong acid HCl What will the pH be if just water and no buffer? pH = 1, dead if this is your blood. HCl H+ + Cl- What removes the H+ to keep the pH near 7? The conjugate base, F- H F HF (a weak acid, low H+ )

Now add the strong base NaOH
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. H+ HF Na+ F- HF (g)  H+ + F- 1.0 L small Large OH- Na+ NaF (s) Na+ + F- Now add the strong base NaOH What will the pH be if just water and no buffer? NaOH Na+ + OH-

Now add the strong base NaOH
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water. H+ HF Na+ F- HF (g)  H+ + F- 1.0 L small Large OH- Na+ NaF (s) Na+ + F- Now add the strong base NaOH What will the pH be if just water and no buffer? PH = 13, dead again NaOH Na+ + OH- What removes the OH- to keep the pH near 7? The acid HF HF + OH F- + HOH

Titration Titration is an experimental procedure to determine the concentration of an unknown acid or base. The figure on the left shows the glassware for a titration experiment. A buret clamp holds the buret to a ring stand and below the buret is a flask containing the solution to be titrated, which includes an indicator. The purpose of the indicator is to indicate the point of neutralization by a color change.

The picture on the left shows the tip of a buret, with air bubble, which is not good, and also shows the stop-cock. Note the position of the stop-cock is in the “off” position. This picture shows the color of the phenolphthalein indicator at the end-point. In this experiment a mL aliquot of M NaOH titrant is added to 5.00 mL of an unknown HCL solution. The acid solution in the beaker starts out clear and becomes pink when all of the HCL has been consumed. NaOH + HCl  NaCl + HOH

How can we calculate the concentration of acid in the beaker?
Titration How can we calculate the concentration of acid in the beaker?

Titration How can we calculate the concentration of acid in the beaker? Normal procedure, yes, a conversion. Steps 1-4, again!

Normal procedure, yes, a conversion. Steps 1-4, again! 0.100 mole NaOH L NaOH solution

Normal procedure, yes, a conversion. Steps 1-4, again! 0.100 mole NaOH 10-3 L solution L NaOH solution mL solution

Normal procedure, yes, a conversion. Steps 1-4, again! 0.100 mole NaOH 10-3 L solution 23.00 mL soln L NaOH solution mL solution

Normal procedure, yes, a conversion. Steps 1-4, again! 10-3 L solution 23.00 mL soln mole HCl 0.100 mole NaOH L NaOH solution mL solution mole NaOH

Normal procedure, yes, a conversion. Steps 1-4, again! 10-3 L solution 23.00 mL soln mole HCl 0.100 mole NaOH mole NaOH L NaOH solution mL solution

Normal procedure, yes, a conversion. Steps 1-4, again! 0.100 mole NaOH 10-3 L solution 23.00 mL soln mole HCl mL HCl soln. L NaOH solution mL solution mole NaOH 10-3 L HCl soln.

Normal procedure, yes, a conversion. Steps 1-4, again! 0.100 mole NaOH 10-3 L solution 23.00 mL soln mole HCl mL HCl soln. L NaOH solution mL solution mole NaOH 10-3 L HCl soln. 5.00 mL

Normal procedure, yes, a conversion. Steps 1-4, again! = 0.100 mole NaOH 10-3 L solution 23.00 mL soln mole HCl mL HCl soln. mole NaOH 10-3 L HCl soln. 5.00 mL L NaOH solution mL solution 0.460 M HCl

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added?

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- Less pink colorless pink Describe the color change when a strong acid is added?

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added? Describe the color change when a strong base is added? Less pink

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added? Describe the color change when a strong base is added? Less pink Darker pink

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added? Describe the color change when a strong base is added? Describe the color change when the pH is lowered? Less pink Darker pink

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added? Describe the color change when a strong base is added? Describe the color change when the pH is lowered? Less pink Darker pink Less pink

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added? Describe the color change when a strong base is added? Describe the color change when the pH is lowered? Describe the color change when the pH is raised? Less pink Darker pink Less pink

Indicators Indicators are weak organic (carbon containing) acids of various colors depending on the formula of the acid. Below is a generic acid. HA  H+ + A- colorless pink Describe the color change when a strong acid is added? Describe the color change when a strong base is added? Describe the color change when the pH is lowered? Describe the color change when the pH is raised? Less pink Darker pink Less pink Darker pink

Color versus pH of Many Different indicators

How can we make an indicator?

How can we make an indicator?
Step Two Step Three Step One Red Cabbage Cook the Cabbage Filter the Juice

What color is the juice after filtering?

Colors of cabbage juice at various pH values
What color is the juice after filtering? The color of pH 6, 7, or 8 Colors of cabbage juice at various pH values

The End Ch#14 Acids Bases and Salts

Chapter #14 Acids, Bases, and Salts.

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Chapter #14 Acids, Bases, and Salts.

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