CHAPTER 13
SOLUTIONS
SOLUTION REVIEW
Solutions are homogenous mixtures.
 They consist of a larger component called the
solvent and one or more smaller components called
the solutes.
 Can be in the solid, liquid, or gaseous state.
Solution Examples
•Margarine
•Tap Water
•Steel
•18 Carat Gold
•Air
•Sterling Silver
Solution Examples
Composition of air: Dry air contains roughly (by volume)
78% nitrogen, 21% oxygen, 0.93% argon,
0.038% carbon dioxide, and small amounts of other gas
Air also contains a variable amount of water vapor,
on average around 1%
What is the solvent in air ?
Solution Examples
Composition of air: Dry air contains roughly (by volume)
78% nitrogen, 21% oxygen, 0.93% argon,
0.038% carbon dioxide, and small amounts of other gases.
Air also contains a variable amount of water vapor,
on average around 1%
What is the solvent in air ?
Nitrogen, N2
Solution Examples
Composition of air: Dry air contains roughly (by volume)
78% nitrogen, 21% oxygen, 0.93% argon,
0.038% carbon dioxide, and small amounts of other gases.
Air also contains a variable amount of water vapor,
on average around 1%
What is the solvent in air ?
Nitrogen, N2
What is a solute in air?
Solution Examples
Composition of air: Dry air contains roughly (by volume)
78% nitrogen, 21% oxygen, 0.93% argon,
0.038% carbon dioxide, and small amounts of other gases.
Air also contains a variable amount of water vapor,
on average around 1%
What is the solvent in air ?
Nitrogen, N2
What is a solute in air?
Oxygen, O2
Solution Examples
Composition of 18 carat gold: 75% gold, 12.5% silver, 12.5% copper.
What is the solvent in 18 ct gold ?
Solution Examples
Composition of 18 carat gold: 75% gold, 12.5% silver, 12.5% copper.
What is the solvent in 18 ct gold ?
Gold
Solution Examples
Composition of 18 carat gold: 75% gold, 12.5% silver, 12.5% copper.
What is the solvent in 18 ct gold ?
Gold
What are the solutes?
Solution Examples
Composition of 18 carat gold: 75% gold, 12.5% silver, 12.5% copper.
What is the solvent in 18 ct gold ?
Gold
What are the solutes?
Silver and Copper
Solution Examples
Examples of solutions include:
Salt water:
what is the solvent in salt water ?
Solution Examples
Examples of solutions include:
Salt water:
what is the solvent in salt water ?
Water, H2O
Solution Examples
Examples of solutions include:
Salt water:
what is the solvent in salt water ?
Water, H2O
What is a solute in sea water?
Solution Examples
Examples of solutions include:
Salt water:
what is the solvent in salt water ?
Water, H2O
What is a solute in sea water?
NaCl (salt)
Solution Properties
Some general properties of solutions include:
 Solutions may be formed between solids, liquids or
gases.
 They are homogenous in composition
 They do not settle under gravity
 They do not scatter light (Called the Tyndall Effect)
Solute particles are too small to scatter light and therefore
light will go right through a solution like is shown on the
next slide.
Tyndall Effect
Laser light reflected by a colloid. In a solution you would not
see any red light.
Solubility
Soluble substances are those that can dissolve in a given
solvent.
Insoluble or immiscible substances are those that cannot
dissolve in a given solvent.
Which of the following are soluble in water?
NaCl, sugar, cooking oil, alcohol, gasoline, motor oil
Solubility
Soluble substances are those that can dissolve in a given
solvent.
Insoluble or immiscible substances are those that cannot
dissolve in a given solvent.
Which of the following are soluble in water?
NaCl, sugar, cooking oil, alcohol, gasoline, motor oil
Solubility
Soluble substances are those that can dissolve in a given
solvent.
Insoluble or immiscible substances are those that cannot
dissolve in a given solvent.
Which of the following are soluble in water?
NaCl, sugar, cooking oil, alcohol, gasoline, motor oil
Which of the following are immiscible in cooking oil?
NaCl, sugar, alcohol, gasoline, motor oil, water
Solubility
Soluble substances are those that can dissolve in a given
solvent.
Insoluble or immiscible substances are those that cannot
dissolve in a given solvent.
Which of the following are soluble in water?
NaCl, sugar, cooking oil, alcohol, gasoline, motor oil
Which of the following are immiscible in cooking oil?
NaCl, sugar, alcohol, gasoline, motor oil, water
Solubility
The maximum amount of a given solute a solvent can dissolve
is called the solubility. The solubility is dependent on the
temperature and pressure.
Solubility is often expressed in terms of grams of solute per
100 g of solvent but may have other units.
When a solvent contains the minimum amount of a solute
possible the solutions is said to be unsaturated.
When a solvent contains the maximum amount of a solute
possible the solutions is said to be saturated.
When a solvent contains more than the maximum amount of
a solute possible the solutions is said to be supersaturated.
Solubility
Solutions form when a soluble solute(s) is dissolved in a
solvent.
In biological systems aqueous (solutions where water is the
solvent) are of particular importance.
The solubility of most liquids and solids in water increases
with temperature.
The effect of pressure on the solubility of liquid or solid
solutes in water is negligible.
Solubility Curves of Various Solutes
Supersaturated Solutions
By forming a solution at a high temperature then slowly
cooling it we can form supersaturated solutions that contain
more solute than in a saturated solution.
These kinds of solutions are very unstable and tend to
separate out the excess solute with the slightest disturbance.
http://www.youtube.com/watch?v=uy6eKm8IRdI&NR=1
http://www.youtube.com/watch?v=aC-KOYQsIvU&feature=related
Solubility
The solubility of gases in water decreases with temperature.
 Are cold carbonated drinks bubblier than warm
carbonated drinks?
The solubility of many gases in water is directly proportional
to the pressure being applied to the solution.
i.e. double the pressure, double the solubility
 What happens when the cork is removed from a
bottle of champagne?
 What is the origin of decompression sickness?
 Anyone heard of hyperbaric therapy?
SOLUTION FORMATION
When we place an ionic solid in water there will be
attractive forces between the ions at the surface of the
crystal and the water molecules. These attractive forces
are called ion-dipole forces.
Water molecules orient such that the positive end of the
molecule is oriented towards the negative ions at the
surface and vice versa.
Solution Formation
How do solutions form?
Why do some substances leave one phase and enter the
solution and others don’t?
How can we use chemistry to predict solubility's?
Lets first look at the formation of a solution between an ionic
solute and a polar solvent such as H2O.
Solution Formation
Ionic compounds are composed of oppositely charged ions
arranged in a repeating 3-d arrangement.
They are held together
by attractive forces
between oppositely
charged ions.
Solution Formation
Ionic compounds are composed of oppositely charged ions
arranged in a repeating 3-d arrangement.
They are held together
by attractive forces
between oppositely
charged ions
Why is chloride ion
larger than sodium ion?
SOLUTION FORMATION
red is the region
where electrons are
found most often and
blue is
where electrons are
rarely found
SOLUTION FORMATION
If the attractive force between the surface ion and the
solvent is greater than the forces between the ion and the
solid then the ion will enter the solution phase.
The ion that has left the solid
H2O and becomes completed
surrounded by water
molecules. It has become
solvated or hydrated.
K+
SOLUTION FORMATION
Note the different
orientation of water
molecules around
the oppositely
charged ions.
Positive pole of
water directed to
the negative ions
and the negative
pole directed to the
positive ions
SOLUTION FORMATION
In a solution of an ionic compound a solvated ion will
occasionally collide with the surface of the solid.
Sometimes when this happens the ion will “stick” to the
surface and become part of the solid phase again.
This will happen more frequently the more concentrated the
solution is.
SOLUTION FORMATION
When the rate of ions leaving the solid equals the rate of ions
going back to the solid the system is at equilibrium and the
solution is saturated.
When a solution is at equilibrium with its solute
macroscopically there will be no change occurring.
However, at the molecular level lots is happening, just in
equal and opposite directions.
SOLUTION FORMATION
Supersaturated solutions can form because there are no sites
for solute ions to collide with.
When we place a “seed” crystal in a supersaturated solution
this provides the needed sites and the excess solute
crystallizes very quickly.
SOLUTION FORMATION
In the you tube video
we watched you can
just see the tiny seed
crystals on the persons
finger.
SOLUTION FORMATION
Polar but non-ionic solutes dissolve in water via a similar
mechanism as for ionic compounds.
SOLUTION FORMATION
A solute will be insoluble in a solvent if:
1. Forces between solute particles are greater than the
forces between solute particles and the solvent.
SOLUTION FORMATION
A solute will be insoluble in a solvent if:
2. Forces between the solvent particles are stronger than
forces between the solvent and the solute.
e.g. The only attractive force between oil and water will is
dispersion forces. These are weak compared to hydrogen
bonds between water molecules.
SOLUTION FORMATION
In a polar solvent
there will be
attraction between
the oppositely
charged ends of the
molecule.
Hydrogen bonds are represented by dotted lines
between the water molecules. A hydrogen bond is and
intermolecular force between hydrogen of one molecule
and O, N, or F of another molecule. Hydrogen must be
directly attached to O, N, or F in at least one of the two
hydrogen bonded molecules.
SOLUTION FORMATION
A good “rule of thumb” that works especially well for nonionic compounds is:
“Like dissolves like”
i.e. Polar solvents dissolve polar solutes well and non-polar
solvents dissolve non-polar solutes well.
SOLUTION RATE
The rate of dissolution is dependent upon:
1. The surface area of the solute.
i.e. how finely divided it is.
Increasing rate
SOLUTION RATE
2. How hot the solution is.
i.e. the kinetic energy of solute and solvent.
3. The rate of stirring.
Typically when we are
preparing a solution in the lab
we will both heat and stir.
SOLUTION RATE
When a solute dissolves in a solvent heat can be released or
absorbed.
When heat is absorbed the process is endothermic and the
solution becomes cooler.
This effect is used in instant cold packs for sporting injuries
and first aid.
HEAT OF SOLUTION
Endothermic Solution
Solvent temperature 22.2°
Solvent temperature 11.3°
HEAT OF SOLUTION
Exothermic Solution
More commonly dissolution is an exothermic process and
heat is released when a solute is dissolved.
Sometimes when we make a solution it will get so hot it
boils!!
SOLUTION CONCENTRATION
The ratio of the amount of solute to amount of solution, or
solvent is defined by the concentration.
Concentration = solute
solution
=
solute
solvent
There are various combinations of units that are used in these
rations.
Ratio
X 102 X 103 X 106 X 109
g solute
g solution
= % (w/w)
g solute
= % (w/v)
mL solution
mL solute
mL solution
=
% (v/v)
ppt (w/w) ppm (w/w) ppb (w/w)
ppt (w/v)
ppm (w/v) ppb (w/v)
ppt (v/v)
ppm (v/v)
ppb (v/v)
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
1. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
33.6g H2O + 25.2 g NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl
100 g solution
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl 333 g solution
100 g solution
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl 333 g solution
100 g solution
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl 333 g solution
= 149 g NaCl
100 g solution
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl 333 g solution
= 149 g NaCl
100 g solution
Mass of water?
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl 333 g solution
= 149 g NaCl
100 g solution
Mass of water? 333 g solution – 149 g NaCl = 184 g H2O
SAMPLE SOLUTION PROBLEMS
1. Find the % (w/w) when 25.2 g NaCl is combined with 33.6g
H2O.
25.2 g NaCl
100
33.6g H2O + 25.2 g NaCl
= 43.0 % NaCl
2. Find the mass of water and salt required to make 333 g of a
44.6 % (w/w) solution.
44.6 g NaCl 333 g solution
= 149 g NaCl
100 g solution
Mass of water? 333 g solution – 149 g NaCl = 184 g H2O
SAMPLE SOLUTION PROBLEMS
3. How many grams of NaCl are required to dissolve in 88.2 g
of water to make a 29.2% (w/w) solution.
4. A sugar solution is 35.2%(w/v) find the mass of sugar
contained in a 432 mL sample of this sugar solution.
SOLUTION CONCENTRATION
The solution concentration can also be defined using moles.
The most common example is molarity (M).
The molarity of a solution is defined as:
“The number of moles of solute in 1 L of solution”
and is given the formula:
Molarity (M) =
Moles solute
Liters solution
MOLARITY SAMPLE PROBLEMS
1. A student dissolves 25.8 g of NaCl in a 250 mL volumetric
flask. Calculate the molarity of this solution. (picture of
volumetric flask is on the next slide)
2. Find the mass of HCl required to form 2.00 L of a 0.500 M
solution of HCl.
3. A student evaporates the water form a 333 mL sample of a
0.136 M solution of NaCl. What mass of salt remains?
4. Find the molarity of sodium ions in a 0.841 N solution of
Na2SO4.
SOLUTION PREPARATION
In the lab we would use a piece of glassware called a volumetric flask to
prepare this solution.
SOLUTION PREPARATION
VOLUMETRIC FLASK
SOLUTION DILUTION
Often we will want to make a dilute solution from a more
concentrated one.
To determine how to do this we use the formula :
C1V1 = C2V2
Where:
C1 = concentration of more concentrated solution
V1 = volume required of more concentrated solution
C2 = concentration of more dilute solution
V2 = volume of more dilute solution
We can use any units in this equation but they must be the
same on both sides.
DILUTION PROBLEM
How would one prepare 50.0 mL of a 3.00 M solution of
NaOH using a 7.10 M stock solution?
C1V1 = C2V2
(7.10 M)V1 = (3.00 M) (50.0 mL)
(7.10
M)V1 = (3.00 M) (50.0 mL)
(7.10 M)
(7.10 M)
V1 = 21.1 mL
This means that you add 21.1 mL of the concentrated stock solution to a
50.0 mL volumetric flask and add water until the bottom of the meniscus
touches the line on the volumetric flask.
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) → 2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) → 2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
0.100 moles AgNO3
L solution
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) →2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
0.100 moles AgNO3 L solution
L solution
103 mL
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) → 2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
0.100 moles AgNO3 L solution 2moles AgCl 143.35 g AgCl 33.2 mL
L solution
103 mL 2moles AgNO3 moles AgCl
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) → 2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
0.100 moles AgNO3 L solution 2 moles AgCl 143.35 g AgCl 33.2 mL
2 moles AgNO3moles AgCl
L solution
103 mL
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) → 2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
0.100 moles AgNO3 L solution 2 moles AgCl 143.35 g AgCl 33.2 mL
2 moles AgNO3 moles AgCl
L solution
103 mL
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) → 2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
0.100 moles AgNO3 L solution 2 moles AgCl 143.35 g AgCl 33.2 mL
2 moles AgNO3 moles AgCl
L solution
103 mL
= 0.476 g AgCl
Solution Stoichiometry
Consider the following balanced equation:
CaCl2 (aq) + 2 AgNO3 (aq) →2 AgCl (s) + Ca(NO3)2 (aq)
1. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and an excess of calcium
chloride.
2. Find the mass of silver chloride formed from 33.2 mL of a
0.100 M solution of silver nitrate and 200.0 mL of a 0.200
M solution of calcium chloride solution.
3. Find the volume of the excess reactant.
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.
NaOH + HCl  NaCl + HOH
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.
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!
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
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
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 23.00 mL soln
mL solution
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 23.00 mL soln mole HCl
mole NaOH
mL solution
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 23.00 mL soln mole HCl
mole NaOH
mL solution
How can we calculate the concentration of acid
in the beaker?
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.
How can we calculate the concentration of acid
in the beaker?
Normal procedure, yes, a conversion. Steps 1-4, again!
0.100 mole NaOH 10-3 L solution 23.00 mL soln mole HCl
L NaOH solution
mL solution
mL HCl soln.
mole NaOH 10-3 L 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 10-3 L solution 23.00 mL soln mole HCl
mL HCl soln.
mole NaOH 10-3 L HCl soln.
L NaOH solution mL solution
5.00 mL
=
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+ + Acolorless
1.
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+ + Acolorless
1.
Less pink
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+ + Acolorless
pink
1.
Describe the color change when a strong acid is added? Less pink
2.
Describe the color change when a strong base 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+ + Acolorless
pink
1.
Describe the color change when a strong acid is added? Less pink
2.
Describe the color change when a strong base is added? 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
1.
Describe the color change when a strong acid is added? Less pink
2.
Describe the color change when a strong base is added? Darker pink
3.
Describe the color change when the pH is lowered?
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+ + Acolorless
pink
1.
Describe the color change when a strong acid is added? Less pink
2.
Describe the color change when a strong base is added? Darker pink
3.
Describe the color change when the pH is lowered? 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+ + Acolorless
pink
1.
Describe the color change when a strong acid is added? Less pink
2.
Describe the color change when a strong base is added? Darker pink
3.
Describe the color change when the pH is lowered? Less pink
4.
Describe the color change when the pH is raised?
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+ + Acolorless
pink
1.
Describe the color change when a strong acid is added? Less pink
2.
Describe the color change when a strong base is added? Darker pink
3.
Describe the color change when the pH is lowered? Less pink
4.
Describe the color change when the pH is raised? 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
The End Ch#13
Solutions