Chapter 1: Matter—Its Properties and
Measurement
Dr. Leonardo C. Medina, Jr.
Contents
1-1 The Scientific Method
1-2 Properties of Matter
1-3 Classification of Matter
1-4 Measurement of Matter: SI (Metric) System
1-5 Density and Percent Composition:
Their Use in Problem Solving
1-6 Uncertainties in Scientific Measurements
1-7 Significant Figures
Focus On The Scientific
Method at Work: Polywater
1-1 The Scientific Method
• Louis Pasteur (1822-1895)
– Developer of Germ Theory
– Pasteurization
– Rabies Vaccination
• Called the greatest physician
of all time by some.
• He was a chemist by training
and profession.
Figure 1-1 The Scientific Method Illustrated
1-2 Properties of Matter
Matter: Occupies space, has mass and inertia
Composition: Parts or components
ex. H2O, 11.19% H and 88.81% O
Properties: Distinguishing features
physical and chemical properties
1-2 Classification of Matter
• Matter is made of atoms.
• 114 elements.
• About 90% available from natural sources
• Compounds are comprised of two or more elements.
• Molecules are the smallest units of compounds.
Separating Mixtures
Separating Mixtures
General Chemistry: Chapter 1
Decomposing Compounds
General Chemistry: Chapter 1
States of Matter
General Chemistry: Chapter 1
1-4 The Measurement of Matter
Slide 12 of 19 General Chemistry: Chapter 1 Prentice-Hall © 2007
Mass
• Mass is the quantity
of matter in an object.
• Weight is the force of
gravity on an object
Wm W=gm
Temperature
Volume
SI and non-SI Units Compared
1 Imperial qt
1.136 L
1 US qt
1L
0.936 L
1 kg 1 lb
1 in 1 cm
Units
S.I. Units Other Common Units
Length meter, m Length Angstrom, Å, 10-8 cm
Mass Kilogram, kg Volume Liter, L, 10-3 m3
Time second, s Energy Calorie, cal, 4.184 J
Temperature Kelvin, K Pressure
Quantity Mole, 6.0221023 mol-1 1 Atm = 1.064 102 kPa
1 Atm = 760 mm Hg
Derived Quantities
Force Newton, kg m s-2
Pressure Pascal, kg m-1 s-2
Energy Joule, kg m2 s-2
1-5 Density and Percent Composition
= m/V
m=V V=m/
g/mL
Mass and volume are extensive properties
Density is an intensive property
Density in Conversion Pathways
What is the mass of a cube of osmium that is 1.25
inches on each side?
Have volume, need density = 22.48g/cm3
EXAMPLE 1-2
Relating Mass, Volume and Density
The stainless steel in the solid cylindrical rod pictured below has
a density of 7.75 g/cm3. If we want a 1.00 kg mass of this rod,
how long a section must we cut off?
m 1
Calculate the Volume needed V= = m
d d
Calculate the Length V = hr2 h = V2
r
EXAMPLE 1-2
m 1
Calculate the Volume needed V= d = m d
1 cm3
V = = (1.00kg)(1000g/kg) 7.75 g = 129 cm3
V
Calculate the Length V = hr2 h=
r2
V 129 cm 3
h= = = 25.5 cm
r2 (3.1415){(0.5)(1.000 in)(2.54 cm/in)} 2
Measuring Volume of an Irregular Object
1-6 Uncertainties in Scientific Measurements
• Systematic errors.
– Thermometer constantly 2°C too low.
• Random errors
– Limitation in reading a scale.
• Precision
– Reproducibility of a measurement.
• Accuracy
– How close to the real value.
Precision
Reproducibility 0.1 g 0.0001 g
Precision low high
1-7 Significant Figures
Significant Figures
The calculators show the effect of the change in a low precision
number in a calculation 14.79 12.11 5.05
5.04 5.05 5.06
