College of Technology & Allied Sciences
AS 1 GENERAL CHEMISTRY
Bohol Island State University- Main
Chapter 1: INTRODUCTION TO THE STUDY OF CHEMISTRY

Chemistry is the study of matter and its properties, the changes that matter undergoes, and the energy
associated with those changes (Silberberg, 3 rd ed., p. 3).
Activity 1: Chemistry in the House
Explore the objects in your house. Which among them do you think are related to chemistry? On a long
bondpaper, list as many of these objects as you can. Beside the name of each object, write a phrase or sentence
that explains why you say the object is related to chemistry. Present your answers using the table below.
Object
Relation to Chemistry
 Chemistry has a central role among the sciences.
Paleontology
Neurology
Geology
Medicine
Physics
Electronics
Archaeology
Ecology
Meteorology
CHEMISTRY
Agriculture
Metallurgy
Botany
Engineering
Biology
Toxicology
Biochemistry
Pharmacology
Figure 1.1. Role of Chemistry Among Sciences
Science is a unified whole. Common scientific laws apply everywhere and on all levels of
organization. The various areas of science interact and support one another. Accordingly, chemistry not only is
useful to itself but is also fundamental to other scientific disciplines. The application of chemical principles has
revolutionized biology and medicine, has provided materials for powerful computers used in mathematics, and
has profoundly influenced other fields such as psychology. The social goals of better health and more and better
food, housing, and clothing are depended to the large extent on the knowledge and techniques in chemistry.
Chemistry is indeed a central science. There is scarcely a single area of our daily lives that is not affected by
chemistry.
Activity 2: Contributions of Chemistry through Time
Concentrate on your field/specialization. Make a timeline showing the contributions of chemistry in your
major/ specialization (e.g. Food technology, electronics, etc.). You can either use cut-outs or computer graphics to
present your timeline in chemistry. Show your creativity. Put in a long bondpaper.
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College of Technology & Allied Sciences
AS 1 GENERAL CHEMISTRY
Bohol Island State University- Main
Scientific Method
– a process involving creative propositions & tests aimed at objective, verifiable discoveries.
Hypothesis is revised if
experimental results
do not support it.
Observations
Natural phenomena
and measured events
Experiment
Procedure to test
hypothesis
Hypothesis
Tentative proposal that
explains observations
Further Experiment
Tests predictions based on
model
Model (Theory)
Set of conceptual assumptions
that explains data from
accumulated experiments
Model is altered if
predicted events do
not support it.
Figure 1.2. The Scientific Method




Observations. These are facts our ideas must explain.
Hypothesis. Whether derived from observation or from a “spark of intuition”, a hypothesis is a
proposal made to explain an observation. A sound hypothesis need not to be correct, but it must be
testable by experiment. Indeed, a hypothesis is often the reason for performing an experiment: if the
results do not support it, the hypothesis must be revised or discarded. Hypotheses can be altered, but
experimental results cannot.
Experiment. A set of procedural steps that tests a hypothesis, an experiment often leads to revised
hypothesis and new experiments to test it. Experimental results must be reproducible by others. Both
skill and creativity play a part in experimental design.
Model. Formulating conceptual models, or theories, based on experiments that test hypotheses about
observations distinguishes scientific thinking from speculation. As hypotheses are revised according
to experimental results, a model emerges to explain how the phenomenon occurs. A model is a
simplified, not an exact, representation of some aspect of nature that we use to predict related
phenomena. Ongoing experimentation refines the model to account for new facts.
Classification of Matter
Figure 1.3. Classification of Matter
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College of Technology & Allied Sciences
AS 1 GENERAL CHEMISTRY
Bohol Island State University- Main

Matter is anything that occupies space and has mass. Matter includes things we can see and touch
(such as water, earth, and trees), as well as things we cannot (such as air). Thus, everything in the
universe has a “chemical” connection.
 Mixture is a combination of two or more substances in which the substances retain their distinct
identities. Some familiar examples are air, soft drinks, milk, and cement. Mixtures do not have
constant composition. Therefore, samples of air collected in different cities would probably differ
in composition because of differences in altitude, pollution, and so on. Mixtures are either
homogeneous or heterogeneous.
 Homogeneous mixture (solutions) - no visible parts; composition of mixture is same
throughout (e.g. coffee dissolved in water, air)
 Heterogeneous mixtures- with visible parts; composition of mixture not uniform (e.g. sand
mixed with iron filings, halo-halo)
** Mixtures can be separated into pure substances by physical methods. Examples of these methods are:
1. Evaporation – used to separate components of a mixture with a dissolved solid in a liquid
2. Distillation – used to separate components of a liquid mixture by a process of heating and
cooling, which exploits the differences in the volatility of each of the component (volatility is
synonymous to how fast your substance evaporates)
3. Filtration - used to separate components of a mixture containing an undissolved solid in a
liquid
4. Chromatography – used to separate mixtures of dissolved substances that have different
colors

Pure substance is a form of matter that has a definite (constant) composition and distinct
properties. Examples are water, ammonia, table sugar (sucrose), gold, and oxygen. Substances
differ from one another in composition and can be identified by their appearance, smell, taste, and
other properties. Pure substances can be either elements or compounds.
 Compound- a substance composed of atoms of two or more elements chemically united in
fixed proportions (e.g. water- H2O, table salt- NaCl)
 Element- is a substance that cannot be separated into simpler substances by chemical
means (e.g. Hydrogen- H; gold-Au)
** Compounds can be separated into elements by chemical methods/ chemical reaction.
Activity 3: Classification of Matter Chart
Complete the Classification of Matter chart below.
Matter
Can it be separated by physical
means?
Yes
No
__________________
__________________
_
_
Is the composition
uniform?
Yes
_____________
mixtures
(salt solution)
Can it be decomposed by
ordinary chemical means?
No
_____________
mixtures
(sand & gravel)
Yes
No
_____________
_____________
(carbon dioxide)
(carbon)
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College of Technology & Allied Sciences
AS 1 GENERAL CHEMISTRY
Bohol Island State University- Main
States of Matter
Figure 1.4. States of Matter



Solid- molecules are held close together in an orderly fashion with little freedom of motion; fixed shape
Liquid- molecules are held close together but not rigidly in position & can move past one another
Gas- molecules are separated by distances that are large; freely moving
Table 1.1. Properties of Solid, Liquid and Gas
Property
Compressibility
Density
Volume
Liquid
Gas
almost incompressible
slightly compressible
highly compressible
high
high
very low
definite volume; does not
fill container
assumes shape of
container
retains own volume
Shape
retains own shape
Diffusion
Expansion
Solid
fills the container
assumes shape of
container
extremely slow; occurs
only at surface
slow
rapid
low expansion on heating
low expansion on heating
high expansion on heating
The three states of matter can be interconverted without changing the composition of the substance as
shown below:
SOLID
Vaporization
LIQUID
GAS
Condensation
Figure 1.5. Changes in the States of Matter
Upon heating, a solid (for example, ice) will melt to form a liquid (water). (The temperature at which this
transition occurs is called the melting point.) Further heating will convert the liquid into a gas. (This conversion
takes place at the boiling point of the liquid.) On the other hand, cooling a gas will cause it to condense into a
liquid. When the liquid is cooled further, it will freeze into the solid form.
Figure 1.6. The three states of
matter in water. A hot poker
changes ice into water
and steam.
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College of Technology & Allied Sciences
AS 1 GENERAL CHEMISTRY
Bohol Island State University- Main
Activity 4: What happens?
What happens at the particle level in each of the following events? For each event, draw two particle
pictures of the object to represent how it looks at the start and end of the vent described. Write a short
explanation.
1. A crayon left on the sidewalk on a very hot sunny day.
START
END
Explanation:
2. A woman places several mothballs in a resealable bag and seals the bag. One week later, she notices that
the bag has become inflated and the mothballs are much smaller.
END
START
Explanation:
Properties of Matter
Substances are identified by their properties as well as by their composition. Properties are characteristics
that give each substance its unique identity. These can either be physical or chemical.
Substance’s Properties
Physical Properties
- Characteristics
a
substance
shows by itself, without changing
into or interacting with another
substance
(e.g. color, melting point, boiling
point)
*For example, we can measure the
melting point of ice by heating a block of
ice and recording the temperature at
which the ice is converted to water.
Chemical Properties
- Characteristics a substance shows as
it changes into or interacts with
another substance
(e.g.
flammability,
toxicity,
reactivity)
*For example, the statement “Hydrogen gas
burns in oxygen gas to form water” describes
a chemical property of hydrogen, because to
observe this property, we must carry out a
chemical change, in this case burning.
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College of Technology & Allied Sciences
AS 1 GENERAL CHEMISTRY
Physical Change
- Occurs when a substance
alters its physical properties,
not its composition
Ex. melting of wax, grinding solids to
powders, sugar dissolves in coffee
Bohol Island State University- Main
Chemical Change/ Chemical Reaction
- Substance is converted into
different substance
Ex. rusting of iron, burning, food being
digested or cooked, rotting of banana
All measurable properties
Extensive Property
- Depends on how much
matter is being considered
- Values
of
the
same
extensive property can be
added together
Intensive Property
- Does not depend on how
much matter is being
considered
- Values are not additive
Ex. temperature, density
Ex. mass, volume, heat
Activity 5: Properties of an element
Classify the following properties of an element X as physical or chemical property:
a. Blue-gray color
f. Denser than water
b. Brittle
g. Combines with oxygen
c. Does not dissolve in water
h. Does not oxidize
d. Melts at 1410° C
i. Pressure at 14 psi
e. Reacts vigorously with fluorine
j. Forms acid with hydrogen
Classify the following changes as physical or chemical change:
a. Shredding paper
f. Breaking glass
b. Mixing baking soda and vinegar
g. Sublimation of dry ice
c. Boiling water
h. Milk going sour
d. Baking a cake
i. Leaves of trees becoming yellow
e. Cooking an egg
j. Vaporizing liquid nitrogen
References:
Chang, R. Chemistry. 10th Edition. New York: McGraw Hill 2010
Hill, J.W., McCreary, T.W., Kolb, D.K. Chemistry for Changing Times. 12 th Edition. Pearson Education, Inc. 2010
Ilao, L.V., Lontoc, B.M., Gayon, E.E. General Chemistry 1. Rex Bookstore 2016
Silberberg, M.S. Principles of General Chemistry. 3 rd Edition. New York: International Edition, McGraw Hill 2007
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