CHAPTER 1
Matter & Measurement
General, Organic, & Biological
Chemistry
Janice Gorzynski Smith
CHAPTER 1: Matter & Measurement
Learning Objectives:
 Definition of matter
 Solids, liquids, and gases
 Physical vs chemical properties and changes
 Pure substances: Elements & Compounds
 Mixtures: Heterogeneous vs Homogeneous
 Units of the metric system & common prefixes
 Measured vs exact numbers
 Significant figures: identify & use in calculations
 Scientific Notation
 Conversion factors for calculations to cancel units
 The three temperature scales
 Density and Specific Gravity
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Smith. General Organic & Biolocial Chemistry 2nd Ed.
Matter
Definition
Matter is anything that has mass and takes up volume.
Naturally occurring:
•cotton
•sand
•digoxin, a cardiac drug
Smith. General Organic & Biolocial Chemistry 2nd Ed.
Synthetic (human-made):
•nylon
•Styrofoam
•ibuprofen
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Matter
Solids, Liquids, Gases
The Solid State:
The Liquid State:
• A solid has a definite
volume.
• A liquid has a
definite volume.
• It maintains its shape
regardless of its
container.
• It takes the shape
of its container.
• Solid particles lie close
together in a regular
pattern.
Smith. General Organic & Biolocial Chemistry 2nd Ed.
The Gas State:
• A gas has no definite
shape; it assumes the
shape of its container.
• It has no definite
volume; it assumes
the volume of its
• Liquid particles are
close together but can container.
• Gas particles are very
move past one
far apart and move
another.
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around randomly.
Matter
Physical Properties
Physical properties can be observed or measured
without changing the composition of the material.
•color
•boiling point
•melting point
•odor
•solubility
•state of matter
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Matter
Chemical Properties
Chemical properties determine how a substance can
be converted into another substance.
Chemical change is the chemical reaction that
converts one substance into another (Chapters 5
and 6).
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Matter
Pure Substances: Elements
Pure Substances
• A pure substance is
composed of only a
single component (atom or
molecule).
An element is a pure
substance that cannot be
broken down by a chemical
change.
• It has a constant composition,
regardless of
sample size or origin of
sample.
• It cannot be broken down
to other pure substances
by a physical change.
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aluminum metal (Al)
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Matter
Pure Substances: Compounds
A compound is a pure substance formed by
chemically joining two or more elements.
table salt (NaCl)
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Matter
Mixtures
All matter can be classified as either a pure substance
or a mixture.
Mixtures
• Mixtures are composed of more than one
component.
• They can have varying composition (any
combination of solid, liquid, and gas).
• Mixtures can be separated into their components
by a physical process.
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Matter
Mixtures: Heterogeneous & Homogeneous
Homogeneous
Mixture
Heterogeneous
Mixture
Example: simple syrup
Example: vinaigrette
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Matter
http://ridenourmhs.wikispaces.com/ESUnit2
Definition
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Measurements
Metric System
Each type of measurement has a base unit in the
metric system.
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Measurements
Common Prefixes
The prefix of the unit name indicates if the unit is larger
or smaller than the base unit.
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Measurements
Common Prefixes
The base unit of length is the meter (m).
1 kilometer (km) = 1,000 meters (m)
1 km = 1,000 m
1 millimeter (mm) = 0.001 meters (m)
1 mm = 0.001 m
1 centimeter (cm) = 0.01 meters (m)
1 cm = 0.01 m
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Measurements
Common Prefixes
Mass is a measure of the amount of matter in an
object.
Weight is the force that matter feels due to gravity.
The base unit of mass is the gram (g).
1 kilogram (kg) = 1,000 grams (g)
1 kg = 1,000 g
1 milligram (mg) = 0.001 grams (g)
1 mg = 0.001 g
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Measurements
Common Prefixes
The base unit of volume is the liter (L).
1 kiloliter (kL) = 1,000 liters (L)
1 kL = 1,000 L
1 milliliter (mL) = 0.001 liters (L)
1 mL = 0.001 L
Volume = Length x Width x Height
= cm x cm x cm
= cm3
1 mL = 1 cm3 = 1 cc
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Measurements
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Units
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Measurements
Exact Numbers
An exact number results from counting objects or is
part of a definition.
•10 fingers
•10 toes
•1 meter = 100 centimeters
An inexact number results from a measurement or
observation and contains some uncertainty.
•15.3 cm
•1000.8 g
•0.0034 mL
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Measurements
Significant Figures
Significant figures are all the digits in a measured
number including one estimated digit.
All nonzero digits are always significant.
65.2 g
3 sig. figures
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255.345 g
6 sig. figures
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Significant Figures
Measurements
Rule 1: A zero counts as a significant figure when
it occurs:
•between two nonzero digits
29.05 g
4 sig. figures
1.0087 mL
5 sig. figures
•at the end of a number with a decimal place
3.7500 cm
5 sig. figures
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620. lb
3 sig. figures
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Measurements
Significant Figures
Rule 2: A zero does not count as a significant figure
when it occurs:
•at the beginning of a number
0.00245 mg
3 sig. figures
0.008 mL
1 sig. figure
•at the end of a number that does not have a decimal
2570 m
3 sig. figures
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1245500 m
5 sig. figures
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Measurements
Significant Figures:
Multiplication & Division
Multiplication/Division Rules: The answer has the
same number of significant figures as the original number
with the fewest significant figures.
4 sig. figures
351.2 miles
=
5.5 hour
2 sig. figures
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63.854545 miles
hour
Answer must have
2 sig. figures.
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Significant Figures:
Multiplication & Division
Measurements
to be retained
to be dropped
63.854545 miles
hour
first digit to be dropped
If the first digit
to be dropped is:
= 64 miles
hour
2 sig. figures
Answer
Then:
•between 0 and 4
•drop it and all remaining digits
•between 5 and 9
•round up the last digit
to be retained by adding 1
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Measurements
Significant Figures:
Addition & Subtraction
Addition/Subtraction Rules: The answer has the same
number of decimal places as the original number with the
fewest decimal places.
=
Smith. General Organic & Biolocial Chemistry 2nd Ed.
10.11 kg
2 decimal places
3.6 kg
1 decimal place
6.51 kg
answer must have
1 decimal place
6.5 kg
final answer
1 decimal place
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Measurements
Scientific Notation
In scientific notation, a number is written as:
y x 10x
Coefficient:
A number between
1 and 10.
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Exponent:
Any positive
or negative
whole number.
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Measurements
Scientific Notation
•When the exponent x is positive, move the decimal
point x places to the right.
2.800 x 102 =
280.0
•When the exponent x is negative, move the decimal
point x places to the left.
2.80 x 10–2 =
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0.0280
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Conversion Factors
Measurements
• Conversion factor: A term that converts a quantity in
one unit to a quantity in another unit.
original
quantity
x
conversion factor
desired
= quantity
• Conversion factors are usually written as equalities.
2.21 lb = 1 kg
• To use them, they must be written as fractions.
2.21 lb
1 kg
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or
1 kg
2.21 lb
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Measurements
Conversion Factors
Factor-label method: Using conversion factors to
convert a quantity in one unit to a quantity in
another unit.
•units are treated like numbers
•make sure all unwanted units cancel
To convert 130 lb into kilograms:
130 lb
x
original
quantity
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conversion factor
=
? kg
desired
quantity
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Conversion Factors
Measurements
2.21 lb
1 kg
130 lb
x
or
1 kg
2.21 lb
Answer
2 sig. figures
=
59 kg
•The bottom conversion factor has
the original unit in the denominator.
•The unwanted unit lb cancels.
•The desired unit kg does not cancel.
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Temperature
Measurements
Temperature is a measure of how hot or cold an object is.
• Three temperature scales are used:
1. Degrees Fahrenheit (oF)
2. Degrees Celsius (oC)
3. Kelvin (K)
To convert from oC to oF:
oF
= 1.8(oC) + 32
To convert from oC to K:
K = oC + 273
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To convert from oF to oC:
oC = oF − 32
1.8
To convert from K to oC:
oC
= K − 273
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Measurements
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Temperature
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Density
Measurements
Density: A physical property that relates the mass of
a substance to its volume.
density
=
mass (g)
volume (mL or cc)
To convert volume (mL)
to mass (g):
g
mL x
= g
mL
To convert mass (g)
to volume (mL):
mL
g x
= mL
g
density
inverse of density
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Measurements
Specific Gravity
Specific gravity: A quantity that compares the density
of a substance with the density of water at the
same temperature.
specific gravity
=
density of a substance (g/mL)
density of water (g/mL)
•The units of the numerator (g/mL) cancel the
units of the denominator (g/mL).
•The specific gravity of a substance is equal to its
density, but contains no units.
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