Chapter 1
Introduction:
Matter and Measurement
Recommended Text Problems
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1, 17, 25, 29, 35, 37, 39, 41,
45, 47, 51, 55, 63, 69.
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The Study of Chemistry
„
What is Chemistry
Get familiar or memorize
Laws/Principals.
I Do more exercises.
I
Chapter 1_ Introduction: Matter and Measurement
The Study of Chemistry
„
Why study Chemistry
„
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Chemistry provides important
understanding of our World & how it works.
Enhance our understanding of matter
2
Chapter 1_ Introduction: Matter and Measurement
The Study of Chemistry
The Study of Chemistry
„
How…
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Scientific method
development
„
„
A systematic
approach to solving
problems.
Definitions
„
„
„
Hypothesis
Theory
Law
Chapter 1_ Introduction: Matter and Measurement
Matter
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Definition:
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Chapter 1_ Introduction: Matter and Measurement
Properties of Matter
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Physical Properties…
–
Can be observed
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Boiling point, density, mass, volume, etc.
Chapter 1_ Introduction: Matter and Measurement
Properties of Matter
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Chemical Properties…
–
Can only be observed
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Flammability, corrosiveness, reactivity with acid,
etc.
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Chapter 1_ Introduction: Matter and Measurement
Properties of Matter
Types of Properties
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Intensive Properties…
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Density, boiling point, color, etc.
Chapter 1_ Introduction: Matter and Measurement
Properties of Matter
Types of Properties
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Extensive Properties…
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Mass, volume, energy, etc.
5
Chapter 1_ Introduction: Matter and Measurement
Properties of Matter
Types of Changes
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Physical Changes
–
do not change the composition of a
substance.
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Changes of state, temperature, volume, etc.
Chemical Changes
–
result in new substances.
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Combustion, oxidation, decomposition, etc.
Chapter 1_ Introduction: Matter and Measurement
Classifications of Matter
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Chapter 1_ Introduction: Matter and Measurement
Classifications of Matter
Classifications of Matter
Chapter 1_ Introduction: Matter and Measurement
Classifications of Matter
States of Matter
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Chapter 1_ Introduction: Matter and Measurement
Classifications of Matter
Separation of Matter
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Compound
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Example:
Mixture
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Example:
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Chapter 1_ Introduction: Matter and Measurement
Units of Measurement
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SI base units
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Base unit:
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Chapter 1_ Introduction: Matter and Measurement
Units of Measurement
Metric System
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Prefixes convert the base units into units that
are appropriate for the item being measured.
Chapter 1_ Introduction: Matter and Measurement
Units of Measurement
Volume
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The most commonly
used metric units for
volume are the liter (L)
and the milliliter (mL).
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A liter is a cube 1 dm
long on each side.
A milliliter is a cube 1
cm long on each side.
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Chapter 1_ Introduction: Matter and Measurement
Units of Measurement
Density
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Definition:
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The amount of mass in a unite volume of a
substance.
Density of H2O at 4 °C
Chapter 1_ Introduction: Matter and Measurement
Units of Measurement
Temperature
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Definition
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„
„
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A measure of the average kinetic
energy of the particles in a sample.
In scientific measurements, the
Celsius and Kelvin scales are
most often used.
The Celsius scale is based on
the properties of water.
Conversion C, F, K, & arbitrary
scale
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Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
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A state of having limited
knowledge where it is
impossible to exactly describe
existing state or future outcome,
more than one possible
outcome.
Example:
„
The temperature reading of the
thermometer is …
Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
Accuracy versus Precision
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Accuracy
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„
the proximity of a measurement
to
Precision
„
the proximity of several
measurements to
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Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
Significant Figures
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The term significant figures refers to
digits that were measured.
When rounding calculated numbers, we
pay attention to significant figures so
we do not overstate the accuracy of our
answers.
Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
Significant Figures
1.
2.
3.
4.
5.
All nonzero digits are significant.
Zeroes between two significant figures are
themselves significant.
Zeroes at the beginning of a number are never
significant.
Zeroes at the end of a number are significant if a
decimal point is written in the number.
Exact numbers have an infinite number of
significant figures.
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Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
Significant Figures
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Examples:
„
Postage Scale
„
„
Two-pan balance
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3g
2.53 g
Analytical balance
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2.531 g
Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
Significant Figures
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Examples:
„
0.00500
„
0.03040
„
2.30 x 10-5
„
4.500 x 1012
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Chapter 1_ Introduction: Matter and Measurement
Uncertainty in Measurements
Significant Figures
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Addition or subtraction
„
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answers are rounded to the
Multiplication or division
„
answers are rounded to the number of
digits that corresponds to the
Chapter 1_ Introduction: Matter and Measurement
Dimensional Analysis
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General Steps for Dimensional Analysis:
„
„
„
Write out the desired conversion (could be
multiple steps)
Obtain the conversion factor (could be
multiple steps)
Perform the conversion calculation(s)
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Chapter 1_ Introduction: Matter and Measurement
Conversion Factor
Conversion Factor
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„
We use dimensional
analysis to convert one
quantity to another.
Most commonly
dimensional analysis
utilizes conversion factors
(e.g., 1 in. = 2.54 cm)
Chapter 1_ Introduction: Matter and Measurement
Example:
„
To convert 8.00 m to inches,
„
„
convert m to cm
convert cm to in.
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Chapter 1_ Introduction: Matter and Measurement
Example:
„
How many seconds are there in a day?
More Example
„
If you are going 50 miles per hour, how many
feet per second are you traveling?
„
Sometimes both the top and bottom units need to
be converted:
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Practice Make Perfect
„
Your car's gas tank holds 18.6 gallons and is
one quarter full. Your car gets 16 miles/gal.
You see a sign saying, "Next gas 73 miles."
Your often-wrong brother, who is driving, is
sure you'll make it without running out of gas.
You're not so sure and want to do some quick
Calculation…
Definitions
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„
Hypothesis
Theory
Law
Physical Properties
Chemical Properties
Intensive Properties
„
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„
„
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Extensive Properties
Physical Changes
Chemical Changes
Base units
Accuracy
Precision
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