Why study chemistry?
1.
2.
3.
4.
It’s required.
It sounds interesting.
It’s unavoidable.
It truly is the central science.
Introduction: Matter
and Measurement
Chapter 1 BLB 11th
Expectations
Classify matter
 Properties of matter
 g ↔ mL (using density)
 Solve for any variable in a formula.
 Metric unit conversions
 Other conversions: temperature, metricEnglish, etc.
 Identify and work with significant figures.

1.1 The Study of Chemistry
Chemistry is everywhere!
 Matter is everywhere!
 Thus, chemistry matters!

Chemistry involves the study of
matter – its properties and
behavior.
 Macroscopic observations are
rooted in microscopic structure.

The Periodic Table of the Elements
Checking in…
Name an element:
Name a compound:
Name a mixture:
A. There are three atoms making up a water molecule.
B. The water molecule contains atoms of two different
types of elements.
C. A water molecule has more than one bond.
D. A water molecule has a larger mass than the sum of
masses of its constituent atoms.
Molecules
O2, H2O, CO2, C2H5OH, C2H6O2, C9H8O4
 Models shown on p. 4

1.2 Classification of Matter


Matter – anything which has mass
and takes up space.
States of matter (p. 7):
1.
2.
3.
Solid – rigid, regular
Liquid – fluid, irregular
Gas – open, random
Phases of matter
States of Matter
States of Matter
Physical or chemical
separation?
The Periodic Table of the Elements
Elements
Group Activity

Assemble into groups of four or five.

Introduce yourself.

Work together.

Discuss, argue, and intellectually engage.

Record and report your group’s result.
Group Activity
 Describe
 Devise
the contents of the containers.
a plan to determine which liquid is
in each of the two containers.
Description
Strategy for identification
1.3 Properties of Matter
physical – measured or observed without
changing the identity of a substance, e.g.
physical state, color, odor, density, boiling point
 chemical – describes a substance’s reactivity,
e.g. flammability, corrosiveness
 extensive – depends on the amount of matter
present, e.g. mass, volume
 intensive – does not depend on the amount of
matter present, e.g. density, color, temperature

Physical & Chemical Changes

Physical – change in appearance, not in composition,
e.g. phase changes, separation of mixtures: filtration,
distillation, chromatography

Chemical – new substance is formed as the chemical
identities change, e.g. any chemical

Dissolve vs. react
Explode vs. ignite

Physical or chemical?
Helium leaks out of a balloon?
 Growth of plants by photosynthesis?
 Salt added to a bowl of soup?
 Blood turning red upon exposure to air?

Mixture, compound, pure substance?
Fruit punch?
 Sugar?
 Milk?
 Gold?
 Tap water?

1.4 Units of Measurement (SI Units)
Volume
– a derived unit
Angstrom
Å
10-10 m
Temperature Scales
Temperature Conversions
°F → °C
5
C  ( F  32)
9

°C → °F
9
 F  (C )  32
5

°C → K
K  C  273.15

Density
Density – mass per unit volume
D = m/V (g/cm3 or g/mL)
 Measured at a specific temperature
 Useful as a conversion factor (g ↔ mL)
 Most substances become more dense at lower
temperatures.
 Specific gravity – density of a substance
divided by the density of a reference
substance (usually water); no units

Difference in density values is the reason some things float and others sink.
Density of Water
1
0.99
Water, 0.99987
0.97
0.96
0.95
0.94
0.93
0.92
Ice, 0.917
0.91
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
Density (g/mL)
0.98
Temp. (oF)
Calculate the volume (in mL) of 87.6 g
of platinum. (DPt = 21.5 g/cm3)
1.5 Uncertainty in Measurement







Exact numbers have a defined value, e.g. 12-dozen,
2.54 cm/in; 1000 g = 1 kg; count of objects
All measurements have some degree of uncertainty;
inexact
Types of error: systematic & random
The last digit of a measured quantity is uncertain.
The more significant figures, the greater the certainty.
precision – agreement among data
accuracy – agreement of data with true value
Different measuring devices have different
uses and different degrees of accuracy and
precision.
Significant Figures
nonzero numbers
before
zeroes
always significant
never
between always
behind
sometimes
w/decimal – yes
w/o decimal - no
Significant Figures in Calculations
A calculated result can be no more certain
than the data measured.
 Mathematical operations (pp. 23-24)

Averaging
 + and  x and ÷


least number of decimal places
least number of decimal places
least number of sig. figs.
Round off at the end at the end of a multistep problem.
Sig. Fig. examples
1.6 Dimensional Analysis
Problem-solving strategies:
 Estimate and then calculate your answer.
Do the two agree?
 Get your units correct and your answer
should be correct.
 Report to correct number of sig. figs.
 Practice, practice, practice!