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Chapter #14Acids, Bases, and Salts
Acids, Bases and Salts TopicsThe 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 BasesAnalyzing Acids and BasesTitration CalculationsHydrolysis Reactions of SaltsBuffers
History of Acids and BasesIn 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
1. Sour taste
2. Reacts with carbonates to make CO2
3. Reacts with metals to produce H2
4. Turns blue litmus pink
5. Reacts with B substances to make salt water
Substance B
1. Bitter taste
2. Reacts with fats to make soaps
3. Do not react with metals
4. Turns red litmus blue
5. 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.
The Swedish chemist Svante Arrhenius proposed the first definition of acids and bases.(Substances A and B becameknown 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
Arrhenius Theory
What is H+?
+e-
+
Hydrogen (H) Proton (H+)
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 -
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)
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+
Hydronium Ion
Strong Acids and Bases
How can we identify strong acids or bases?
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!
Memorized Strong Acids1. HClO4
2. H2SO4
3. HI
4. HBr
5. HCl
6. HNO3
Memorized Strong BasesHydroxides of group 1 and 2metals, excluding Be and Mg
Strong Acids and Bases
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
HCl (aq) + H2O (l) Cl - ( aq) + H3O+ (aq)
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.
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.
Bronsted Lowry Theory
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?
Autoionization of Water
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:
]OH][O3H[2]O2H[K
2]O2H[
]OH][O3H[
]O2H][O2H[
]OH][O3H[K
Kw = K[H2O]2 = 10-14 This equilibrium lies very much to the left i.e. mostly water. For pure water [OH-] = [H+] = 1 x 10-7 M
Autoionization of Water
]OH][O3H[wK2]O2H[K
2]O2H[
]OH][O3H[
]O2H][O2H[
]OH][O3H[K
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:
Kw is called the ion product of water.
What is the value for the ion product of water?
1.00 gml 18.0 g
mole ml
10-3 L= 55.5 M
Autoionization of Water
]OH][O3H[wK2]O2H[K
2]O2H[
]OH][O3H[
]O2H][O2H[
]OH][O3H[K
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:
Kw is called the ion product of water.
What is the value for the ion product of water?
[H+][OH-] = 10-14
1.00 gml 18.0 g
mole ml
10-3 L= 55.5 M
Autoionization of Water
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 10-14 M2
[H+] = 0.0000001 = 10-7 (how can this be abbreviated further?)
Autoionization of Water
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 10-14 M2
[H+] = 0.0000001 = 10-7 (how can this be abbreviated further?)
By just describing the power
Autoionization of Water
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 10-14 M2
[H+] = 0.0000001 = 10-7 (how can this be abbreviated further?)
By just describing the power Called the power of H, or pH.
Autoionization of Water
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 10-14 M2
[H+] = 0.0000001 = 10-7 (how can this be abbreviated further?)
By just describing the power Called the power of H, or pH.
pH = 7Our math departments tells us that log means power too.
Autoionization of Water
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?
Autoionization of Water
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?
Autoionization of Water
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.
Autoionization of Water
Now for some examples1. Find the pH and pOH, when [H+] = 10-4
Now for some examples1. 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 lineNumber 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
pH = 2[H+] = 10-2
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] = [OH -]neutral
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] = [OH -]neutral
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] < [OH -]basic
[H+] = [OH -]neutral
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] =10-16
[OH -] =
[H+] < [OH -]basic
[H+] = [OH -]neutral
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] =10-16
[OH -] = 102
[H+] < [OH -]basic
[H+] = [OH -]neutral
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] =10-1
[OH -] = 102
[H+] < [OH -]basic
[H+] < [OH -]basic
[H+] = [OH -]neutral
[H+] > [OH -]acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] =10-16
[OH -] = 102
[H+] < [OH -]basic
[H+] < [OH -]basic
[H+] = [OH -]neutral
[H+] > [OH -]acidic
acidic
A pH Number lineNumber 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
pH = 2[H+] = 10-2
[OH -] = 10-12
[H+] = 10-7
[OH -] = 10-7
[H+] =10-12
[OH -] = 10-2
[H+] =10-16
[OH -] = 102
[H+] < [OH -]basic
[H+] < [OH -]basic
[H+] = [OH -]neutral
[H+] > [OH -]acidic
acidic
basic
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) + 2H2O (l)
2HCl (aq) + CaCO3 (aq) CaCl2 (aq) + H2O (l) + CO2 (g)
2HC l (aq) + Sr(HCO3)2 (aq) SrCl2 (aq) + 2H2O (l) + 2CO2 (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.
Equations With Acuids
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)
Ionic Equations (a review)
Another property of acids is their reaction with certain metals to
produce hydrogen gas, H2 (g).
Zn (s) + 2HC 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) + 2H+ (aq) + 2Cl- (aq) H2 (g) + Zn2+ (aq) + 2Cl- (aq)
Net ionic equation:
Zn (s) + 2H+ (aq) H2 (g) + Zn2+ (aq)
Acidic Single Replacement Reactions
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
SaltsSalts 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.
1. NaCl
1. NaC2H3O2
1. NH4Cl
NaCl + HOHReactants are?
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOH
S.A. s.b.
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOH
S.A. s.b.Neutral salt
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOH
Neutral salt s.a. s.b.
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOHw.a. s.b.
Neutral salt s.a. s.b.
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOHw.a. s.b.basic salt
Neutral salt s.a. s.b.
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOHw.a. s.b.basic salt
Neutral salt s.a. s.b.
NH4Cl + HOH
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOHw.a. s.b.basic salt
Neutral salt s.a. s.b.
NH4Cl + HOHNH4OHHCl +
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOHw.a. s.b.basic salt
Neutral salt s.a. s.b.
NH4Cl + HOHNH4OHHCl +s.a. w.b.
SaltsSalts 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.
1. NaCl
2. NaC2H3O2
3. NH4Cl
NaCl + HOHHCl + NaOH
NaC2H3O2 + HOHHC2H3O2 + NaOHw.a. s.b.basic salt
neutral salt s.a. s.b.
NH4Cl + HOHNH4OHHCl +s.a. w.b.acidic salt
Acid, Base, and Salt Hydrolysis
HBr (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq) Acidic, because H+ (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration0.0
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration0.0 ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration0.0 0.0
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
[H+] = ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
[H+] = 0.1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = ?
[H+] = 0.1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = ?
[H+] = 0.1 = 10-1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
[H+] = 0.1 = 10-1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) acidic?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) No, basic OH-
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
[OH - ] = ?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
pOH = ?
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
pOH = - log[OH-]
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
pOH = - log[OH-] = - log[0.2]
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
pOH = - log[OH-] = - log[0.2] = -(-0.698970004)
pOH = 0.7
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
pOH = - log[OH-] = - log[0.2] = -(-0.698970004)
pOH = 0.7
pH = ?
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
Final concentration0.0 0.1 0.2
pOH = - log[OH-] = - log[0.2] = -(-0.698970004)
pOH = 0.7
pH = 14.0 - 0.07 = 13.3
[OH - ] = 0.2
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq) Acidic, basic, or neutral?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Na+ + HOH NaOH (sb) + H+
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Na+ + HOH NaOH (sb) + H+
Na+ + HOH Na+ + OH- + H+
HOH OH- + H+ No Reaction, water cannot make water
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Na+ + HOH NaOH + H+Cannot make strong acids or bases from weak oness.b.
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Na+ + HOH NaOH + H+Cannot make strong acids or bases from weak oness.b.
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Na+ + HOH NaOH + H+Cannot make strong acids or bases from weak ones
F - + HOH HF + OH-
w.a.
Acid, Base, and Salt Hydrolysis
HBr (aq) H+ (aq) + Br - (aq)
0.1 Initial concentration
Final concentration0.0 0.1 0.1
pH = 1
Ca(OH)2 (aq) Ca2+ (aq) + 2 OH- (aq) Initial concentration0.1 0.0 0.0
final concentration0.0 0.1 0.2
pH = 13.3
NaF (aq) Na+ (aq) + F – (aq)Basic, since HF is w.a. and NaOH is s.b.
Will sodium and fluorine ions react with water?
Na+ + HOH NaOH + H+Cannot make strong acids or bases from weak ones
F - + HOH HF + OH- Yes, HF weak acid and OH- is formed, thus basic salt!
w.a.
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq)
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) acidic, basic, or neutral?
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) acidic, basic, or neutral?
HCl + NH4OH NH4Cl + HOH
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) acidic, basic, or neutral?
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Cl- + HOH HCl + OH-
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Cl- + HOH HCl (sa) + OH-
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Cl- + HOH H+ + Cl- + OH-
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
HOH H+ + OH-Again water cannot make water! NR
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Cl- + HOH HCl + OH-
s.a.
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Cl- + HOH HCl + OH-
s.a.
Cannot form s.a. from weaker reactants, thus N.R.
Acid, Base, and Salt Hydrolysis
NH4Cl (aq) NH4+
(aq) + Cl- (aq) Acidic!
HCl + NH4OH NH4Cl + HOHs.a. w.b.
Will the ions from the salt combine with water?
NH4+ + HOH NH4OH + H+
w.b.
This reaction is OK, since a w.b. is formed
Cl- + HOH HCl + OH-
s.a.
Cannot form s.a. from weaker reactants, thus N.R.
Since H+ was formed in the first reaction, then [H+] is now
greater than [OH-] making the solution acidic
Acid, Base, and Salt Hydrolysis
NaCl (aq)
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq)
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Acidic, basic, or neutral?
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Acidic, basic, or neutral?
HCl + NaOH NaCl + HOH
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Acidic, basic, or neutral?
HCl + NaOH NaCl + HOHs.a. s.b.
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
s.b.
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
s.b.
Cannot form strong bases from weaker ones, thus N.R.
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
s.b.
Cannot form strong bases from weaker ones, thus N.R.
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
s.b.
Cannot form strong bases from weaker ones, thus N.R.
Cl- + HOH HCl + OH-
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
s.b.
Cannot form strong bases from weaker ones, thus N.R.
Cl- + HOH HCl + OH-s.a.
Acid, Base, and Salt Hydrolysis
NaCl (aq) Na+ (aq) + Cl- (aq) Neutral!
HCl + NaOH NaCl + HOHs.a. s.b.
Now react each of the ions with water.
Na+ + HOH
NaOH + H+
s.b.
Cannot form strong bases from weaker ones, thus N.R.
Cl- + HOH HCl + OH-s.a.
Cannot form strong acids from weaker ones, thus N.R.
Buffers
Buffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions.
BuffersBuffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions.
Our blood must maintain a pH around 7.35-7.45. 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.
BuffersBuffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions.
Our blood must maintain a pH around 7.35-7.45. 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.
BuffersBuffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions.
Our blood must maintain a pH around 7.35-7.45. 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.
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?
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.
BuffersBuffers are extremely important in chemistry and biology. They maintain a nearly consistent pH in various solutions.
Our blood must maintain a pH around 7.35-7.45. 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.
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
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.
Despite the possibility of pH increases or decreases, the body maintains a nearly constant pH of 7.4. 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 7.4. 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 + HOHw.a. c.b.
Despite the possibility of pH increases or decreases, the body maintains a nearly constant pH of 7.4. 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 + HOHw.a. c.b.
NH3 + HCl NH4Cl w.b. c.a.
1.0 L
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.
HF (g) H+ + F-
NaF (s) Na+ + F-
H+ Na+ F-
HFlarge small
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
HFH+
Na+ F-
Now add the strong acid HCl
HCl
large small
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
HFH+
Na+ F-
Now add the strong acid HCl
HCl
HCl H+ + Cl-
H+ Cl-
What will the pH be if just water and no buffer?
Large small
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
H+
HF
Na+ F-
Now add the strong acid HCl
HCl
HCl H+ + Cl-
H+ Cl-
What will the pH be if just water and no buffer? pH = 1, dead if this is your blood.
Large small
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
H+
HF
Na+ F-
Now add the strong acid HCl
HCl
HCl H+ + Cl-
H+ Cl-
What will the pH be if just water and no buffer? pH = 1, dead if this is your blood.
Large small
What removes the H+ to keep the pH near 7?
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
H+
HF
Na+ F-
Now add the strong acid HCl
HCl
HCl H+ + Cl-
H+ Cl-
What will the pH be if just water and no buffer? pH = 1, dead if this is your blood.
Large small
What removes the H+ to keep the pH near 7? The conjugate base, F-
H+ + F- HF (a weak acid, low H+ )
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
H+
HF
Na+ F-
Now add the strong base NaOH
NaOH
Na+ OH-Large small
What will the pH be if just water and no buffer?
NaOH Na+ + OH-
1.0 L
Buffer preparation: Add 0.10 mole HF (g) and NaF (s) to 1.0 L of water.
HF (g) H+ + F-
NaF (s) Na+ + F-
H+
HF
Na+ F-
Now add the strong base NaOH
NaOH
Na+ OH-Large small
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
TitrationTitration 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 23.00 mL aliquot of 0.1000 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?
Normal procedure, yes, a conversion. Steps 1-4, again!
Titration
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOHL NaOH solution
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOHL NaOH solution
10-3 L solutionmL solution
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4,
again!
0.100 mole NaOHL NaOH solution
10-3 L solutionmL solution
23.00 mL soln
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4,
again!
0.100 mole NaOHL NaOH solution
10-3 L solutionmL solution
23.00 mL solnmole NaOHmole HCl
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOHL NaOH solution
10-3 L solution
mL solution
23.00 mL solnmole NaOHmole HCl
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOHL NaOH solution
10-3 L solutionmL solution
23.00 mL solnmole NaOHmole HCl
10-3 L HCl soln.mL HCl soln.
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOH
L NaOH solution
10-3 L solution
mL solution
23.00 mL soln
mole NaOH
mole HCl
10-3 L HCl soln.
mL HCl soln.
5.00 mL
How can we calculate the concentration of acid in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOH
L NaOH solution
10-3 L solution
mL solution
23.00 mL solnmole NaOHmole HCl
10-3 L HCl soln.mL HCl soln.
5.00 mL=
0.460 M HCl
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
Less pink
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
2. Describe the color change when a strong base is added?
Less pink
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
2. Describe the color change when a strong base is added?
Less pink
Darker pink
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
2. Describe the color change when a strong base is added?
3. Describe the color change when the pH is lowered?
Less pink
Darker pink
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
2. Describe the color change when a strong base is added?
3. Describe the color change when the pH is lowered?
Less pink
Darker pink
Less pink
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
2. Describe the color change when a strong base is added?
3. Describe the color change when the pH is lowered?
4. Describe the color change when the pH is raised?
Less pink
Darker pink
Less pink
IndicatorsIndicators 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
1. Describe the color change when a strong acid is added?
2. Describe the color change when a strong base is added?
3. Describe the color change when the pH is lowered?
4. 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 One
Red Cabbage
Step Two
Cook the Cabbage
Step Three
Filter the Juice
What color is the juice after filtering?
What color is the juice after filtering? The color of pH 6, 7, or
8
Colors of cabbage juice at various pH values
ACIDS BASES AND SALTS
The End Ch#14