Chemistry 161
Lecture 1: Types of Matter – Macroscopic and Atomic Views
Sections 1.1, 1.2 in Gilbert, Kirss, Foster, and Davies 2nd edition
09/25/08
HW #1: 1.6, 1.10, 1.14, 1.20, 1.28, 1.38, 1.48, 1.62, 1.64, 1.84
Learning Objectives:
1. Define the basic terms associated with matter
2. Identify the principal elements
3. Introduce the means of representing chemical formulas
1.1 & 1.2: What’s the Matter?
Matter: Has mass and takes up space
Chemistry: The fundamental study of matter. By fundamental, we refer to
the modern view of chemistry based on the building blocks found in the
periodic table (from the Greek atomos, meaning “not to cut”). The idea of
the indivisible unit was put forward by Democritus, ca. 460 – 370 BC
The Classification of Matter

Please refer to figure 1.1

Compound is a “catch all” for any pure non-elemental substance.
Properly, the term molecule is reserved for covalently bonded species
o Covalent species are ones which share electrons to achieve a
noble gas electronic configuration – much more on this is critical
concept to come

The importance of homogeneity in terms of concentration and
delivering accurate quantities:
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Familiar groups and elements you will want to know:

Important Elements Based on Group Behavior/Position in the Periodic
Table
o Bear in mind that the elemental forms are not necessarily found
in nature; in fact, with the exception of a few native metals (Au
being one of them); the nonmetals N2, O2 & S; and the noble
gases, elemental forms are quite rare
o Alkali Metals:
o Alkaline Earth Metals:
o Group 16:
o Halogens:
o Noble Gases:
o Periods 1, 2, and 3:
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On Depicting Chemical Compounds
Chemical Formula
 Iron(III) oxide (rust)
 Magnesium sulfate heptahydrate (epsom salts)
 Acetic acid (main component in vinegar)
 Pentane (first liquid saturated hydrocarbon)
Structural formula
 Iron(III) oxide (rust)
 Magnesium sulfate heptahydrate (epsom salts)
 Acetic acid (main component in vinegar)
 Pentane (first liquid saturated hydrocarbon)
Condensed Structural Formula
 Acetic acid (main component in vinegar)
 Pentane (first liquid saturated hydrocarbon)
Line-angle formula
 Acetic acid (main component in vinegar)
 Pentane (first liquid saturated hydrocarbon)
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Chemistry 161
Lecture 2: Separation of Mixtures, Properties & States of Matter
Sections 1.1, 1.2 in Gilbert, Kirss, Foster, and Davies 2nd edition
09/26/08
Learning Objectives:
1. Define mixtures and introduce means of separating them
2. Differentiate between physical properties, chemical properties,
physical changes, and chemical changes
3. Define intensive vs. extensive properties
4. Describe density as an intensive physical property
5. Describe density as a useful conversion factor to convert between
mass and volume
6. Examine 2 common methods for determining density
 Differential Solubility and Extraction or Filtration
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 Distillation

Chromatography – requires a mobile phase and stationary phase
o Paper
o Thin layer
o Column
o Gas
o Liquid
Question: What physical property is being used to separate mixtures in
chromatography?
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Generally, separating mixtures involves physical changes since the
compounds making up the mixture are not transformed; however, there are
occasions where difficult separations may require reaction before
differences in physical properties are exploited
Sometimes we start with pure compounds and create mixtures, where the
physical properties of the properties of the mixture are greatly preferred
to any of the components

Lotions are mixtures (oil in water emulsions) as are creams (water in
oil emulsion)

In 1937, 107 people, mostly children, died when given sulfanilamide
containing1 diethylene glycol. This incident gave rise to the Food,
Drug, and Cosmetic Act of 1938, which essentially gives the FDA its
statutory authority. Here the mixture was not such a good thing
o Amphipathic defined:
Chemical properties: the tendency of a given atom or molecule to react
under a given set of conditions as well as the characteristics of the
transformation
Physical properties: everything else – color, odor, melting point, boiling point,
density, hardness, electrical conductivity, phase under a given set of
pressure and temperature conditions, etc.
Chemical changes: Chemical reactions, where the bonding between atoms
within a molecule changes
Physical changes: Conversion of atoms or molecules from one phase to
another; generation or purification of mixtures
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The diethylene glycol was intentionally added by the manufacturer, the S.E. Massingill Co.,to help
dissolve the sulfanilamide and sweeten the taste
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A final word on the notion of purity…
Are any substances truly pure? From a practical we establish purity limits as an example, the legal limit for As contamination is 10 PPB, which is equal
to 10 ng/mL or 1 mg/100 L
Density and Dimensional Analysis

Density is defined as d = mass/V

Density is an intensive physical property and an important practical
property of compounds
o Reference texts (CRC Handbook of Chemistry & Physics, Merck
Index, etc) will give values for density, particularly for liquid
compounds. Symbols typically used are d or , with a superscript
indicating temperature
o It is not unusual to see a subscript of 4 when density is listed
(e.g. d 420 = .789). What is being reported is specific gravity and
is a ratio of the density of the compound in question (at the
temperature indicated) to water at 4 oC. Note that specific
gravity has no associated unit and is independent of the forces
of gravity

Density may be used to convert mass to volume or volume to mass; in a
sense it acts as a conversion factor
Question: What is the mass of a liquid that has a volume of 18 mL and has a
density of 1.0 g/mL?
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Question: What is the volume occupied by 18.4 g of concentrated sulfuric
acid, which has density = 1.84 g/mL?
Question: How might you calibrate a 1 mL air displacement pipette, knowing
that water has a density of .997 g/mL at room temperature?
For regularly shaped (easily mathematically defined) objects, density may be
determined by measuring mass and calculating volume directly. For
irregularly shaped objects, the “Eureka” method is best used.
Question: 00 Buckshot has a nominal diameter of .180” and has a nominal
mass of .567 g for lead shot. What is the density of 00 Buckshot?
Question: What is the density of a gold crown that displaces 102.3 mL and
has a mass of 1974 g?
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