Introduction to Organic and
Biochemistry
(CHE 124)
Reading Assignment
General, Organic, and Biological Chemistry: An Integrated Approach
3rd. Ed. Ramond
Chapter 6
Gasses, Solutions, Colloids, and Suspensions
Work Problems
Chapter 6: 14, 16, 18, 25, 26, 28, 30, 33, 34, 36,38, 40,45, 46, 53, 56, 60
93, 94,95,96,97,98, 99, 100, 101,102,103, 104, 105, 106, 107, 108, 109, 110, 111,
112, 113, 114, 115, 116,
States of Matter
• Solids
– Matter with a fixed volume and shape
• Liquids
– Matter with a fixed volume, indefinite shape.
– A liquid takes on the shape of the container.
• Gases
– Matter with indefinite shape and volume.
– A gas takes on both the shape and volume of the
container.
Changes in State
• Melting - solid → liquid
– Heat of fusion - amount of heat required to melt a
solid.
• Freezing - liquid → solid
• Evaporation - liquid → gas
– Heat of vaporization - amount of heat required to
evaporate a liquid.
• Deposition- gas → solid
• Sublimation - solid → gas
Phase Diagram
• Figure 6.2 p. 177
Pressure of a gas
• Atmospheric Pressure – pressure of column
of air above and around the earth’s surface.
Extends 32 km (20 miles) above sea level.
• STP Standard Temperature and Pressure
– Temp = 0° C
– Pressure = 1 atm.
Pressure Units
• Pressure – force per unit area.
– Pounds per square inch (psi)
• pounds of pressure exerted on the walls of the gas container per square inch of
wall area.
– Millimeters of mercury (mm Hg)
• pressure exerted by air on column of Hg in barometer (see related slide).
– Torr
• 1 Torr = pressure exerted by 1mm Hg at 0oC.
– Atmosphere (atm)
• 1 atm = pressure exerted by a 760 mm column of Hg at 0oC.
– Pascal (Pa) – SI unit.
• 1 Pa = pressure exerted by a film of water 0.1 mm high on the service beneath.
– Bar (bar)
• 1 bar = 105 Pa
• Almost equal to atm.
1 atm = 760 mm Hg = 760 torr = 14.7 psi = 101.3 kPa
Barometer / Manometer
• Barometer – device used to measure
atmospheric pressure.
– The air in atmosphere exerts a force on a
pool of mercury, causing it to rise up the
column.
– Invented by Evangelista Torricelli in 17th
century.
– Atmospheric pressure at sea level = 740 –
760 mm Hg
– Pressure of Hg changes with density, which
is effected by temp.
• Manometer – device used to measure
pressure in a closed system.
– The height of the column of liquid is
proportional to the pressure
– Gas pressure can be more or less than
atmospheric pressure
Vapor Pressure
• Vapor Pressure – the maximum pressure
exerted by a gas formed by evaporation of a
liquid.
– Increases with increasing temperature.
• Boiling Point of a liquid is the temperature at
which the vapor pressure of the liquid equals
the atmospheric pressure.
– Vapor forms in liquid as small bubbles.
• Draw beaker with lid containing liquid.
Autoclave
• Autoclaveis a device
used to sterilize
instruments /
solutions.
– 15 minutes at 1520
torr, 121°C kills most
infectious agents.
Blood Pressure
• Blood pressure is the pressure that blood exerts on
the walls of blood vessels.
• Measured in the brachial artery in the left arm.
• Taking a blood pressure
– Pump sphygmomanometer until flow is constricted.
– Reduce pressure while listening for first flow through the
artery ---systolic pressure.
– Continue reducing pressure until blood flows freely --this is the diastolic pressure
• Blood Pressure = Systolic pressure = 120
Diastolic pressure 80
hypotension = low blood pressure
hypertension = high blood pressure
Gas Laws
•
•
•
•
•
•
Boyle’s law
Gay-Lussac’s Law
Charles’ Law
Avogodro’s Law
Combined Gas Law
Ideal Gas Law
Boyle’s Law
• Boyle’s Law states that for a gas at a fixed temperature;
pressure and volume are inversely proportional
– Robert Boyle (1627 – 1691)
P1V1 = P2V2
P1 = initial pressure
V1 = initial volume
P2 = final pressure
V2 = final volume
Typical Problem: If a syringe has a pressure of 1 atm at 1 mL.
What is the pressure when the volume is 6 mL?
Gay-Lussac’s Law
• Gay-Lussac’s Law states that for a sample of gas with a
constant volume; pressure and temperature are directly related.
– Joseph Gay-Lussac (1778 – 1850)
P1 = P2
T1
T2
P1 = initial pressure
T1 = initial temperature
P2 = final pressure
T2 = final temperature
Typical Problem: A steel tank of known volume is at
temperature of 25°C and has a volume of 1.5 atm. What is the
pressure if the temperature is raised to 50°C?
Charles’ Law
• Charle’s Law states that for a sample of gas at a fixed
pressure; volume and temperature are directly related.
– Jacques Charles (1746 – 1823)
V1 = V2
T1
T2
V1 = initial volume
T1 = initial temperature
V2 = final volume
T2 = final temperature
Typical Problem: If a balloon has a volume of 2.0L at 25°C,
what is the volume after sitting in a - 10°C freezer?
Avogodro’s Law
• Avogodro’s Law at a given temperature and pressure,
volume and the number of moles of gas are directly related.
V1 = V2
n1
n2
V1 = initial volume
n1 = initial number of moles
V2 = final volume
n2 = final number of moles
Typical problem:
Combined Gas Law
• Combined Gas Law – the name says it all.
P1V1 = P2V2
T1
T2
P1 = initial pressure
V1 = initial volume
T1 = initial temperature
P2 = final pressure
V2 = final volume
T2 = final temperature
Ideal Gas Law
Ideal Gas Law states that for any gas, pressure times volume
divided by number of moles times temperture is a constant
(R ).
PV = nRT
P = pressure (atm)
V = volume (L)
n = number of moles
T = temperature (K)
L  atm
R  0.0821
mol  K
Mixtures of Gasses
• Partial Pressure - If two ideal gases are mixed they each
exert the same pressure it would if it were alone in the
container.
Dalton’s Law of Partical Pressure states that
the total pressure of a mixture of gases is the
sum of the partial pressures of its
components.
Ptotal = PA + PB + PC
Matter
• Pure Substance – one element or compound
• Mixture combination of two or more pure
substanaces
– Homogenous mixture uniform distribution.
• Solution – uniform molecular mixture
– Solvent – component in greater amount
– Solute – component in lesser amount. Dissolves in solvent.
– Heterogenous mixture – mixture that is not evenly
distributed.
• Precipitate (ppt) – a solid reaction product.
Molecules may be soluble or insoluble (ppt).
Solubility of solids and liquids
• Soluble – two substances dissolve in one
another
• Insoluble – two substances do not dissolve in
one another.
– Like dissolves like.
– Temperature effects solubility. For a liquid or solid,
as Temp. increases, solubility increases
Solubility of Gas in aqueous solution
• Henry’s Law – solubility of a gas in a liquid is
proportional to the pressure of the gas over
the liquid.
• Increase pressure, increase solubility of gas
in aqueous solution.
• Increase temperature, decrease in solubility
of gas in aqueous solution.
– Hemoglobin enhances O2 solubility in blood by
binding to the oxygen.
Hyperbaric Chambers
• Hyperbaric chambers increase O2 levels by
increases pressure of O2 (high pressure). This
causes an increase oxygen to dissolve in
blood.
– Used to treat
• carbon monoxide poisoning. Displaces CO from
hemoglobin.
• Gas gangrene
• Tetanus
Solution
• Solution – uniform molecular mixture.
– Solute – component in lesser quantity
– Solvent – component in greater quantity
• “Normal” Human Concentration
– Glucose (serum) – 80 – 100 mg / dL
– Lactate – 0.8 – 1.8 mM
– Testosterone
• Male – 300 – 1000 ng / mL
• Female – 30 – 70 ng / mL
• Concentration – the amount of solute
dissolved in a solvent.
Units of Concentration
Unit
Symbol
Definition
Percent (wt /vol)
%
1 g / 100mL = 1%
Parts per thousand
ppt
1 x 103
Parts per million
ppm
1 x 106
Parts per billion
ppb
1 x 109
Molarity
Equivalent
M
Eq.
moles / L
Number of moles of charges
that one mole of a solution
contributes to solution
1 mol Na+ = 1 eq Na+
1 mol Ca2+ = 2 eq. Ca2+
Dilution
• Dilution – addition of more solvent to reduce
the concentration of solute.
V1C1 = V2C2
V1 = initial volume
C1 = initial concentration
V2 = final volume
C2 = final concentration
Solution, Suspension and Colloid
• Solution – uniform molecular mixture.
• Suspension - contain large particles suspended in a liquid.
• Colloid – solution that contains middle size particles
Mixture
Particle size
Solution
Small
(< 1 nm)
Colloid
Intermediate
(1 nm – 1μm)
Suspension
Large
(> 1 μm)
Appearance
Particle
Settling
Separation
of Particles
Clear
No
Cannot be
separated by
filtration or
centrifugation
Usually cloudy NO
Particles may
be separated
by special
filtration or
centrifugation
Cloudy
Separated by
filtration or
centrifugation
Yes