Introduction
CHEM 012: Chemical Principles
Sections 66-78
Fall 2006
Instructor: Dr. Arshad Khan
Office: 107 Chemistry Blg
Phone: (814) 863-9295
Office hours:
Weds. 10:30-noon
or by appt.
Email: kub@psu.edu
TAs will be assisting us with this course &
will be available to help you at their posted
hours
Chem Undergrad Office: 210 Whitmore
(814) 865-9391
Grades
Recitation days: Quiz & Homework
Online skill check tests
3 Midterm exams & a final
Chapter 1
Matter and Measurement
Chem 12
Penn State
Dr. Arshad Khan
States of Matter

Solid


Liquid


Fixed shape, fixed volume, incompressible,
particles are closely spaced and strongly held.
No fixed shape, fixed volume, almost
incompressible, particles are less strongly held.
Gas

No fixed shape, no fixed volume, compressible,
particles are loosely held
States of Matter
SI Units

Length : Meter (m)

Mass: Kilogram (kg)
Prefixes used in Metric System










Giga (G):
Mega (M):
Kilo (K):
Deci (d):
Centi (c):
Milli (m) :
Micro (μ) :
Nano (n) :
Pico (p) :
Femto (f) :
109
106
103
10-1
10-2
10-3
10-6
10-9
10-12
10-15
Note: 1 kg = 103 g
1 km = 103 m
Temperature Scales
K = oC + 273.15
oC = (5/9) (oF – 32) or oF = (9/5) (oC) + 32
(100 div./180 div.)
Density
Density = Mass (g) / Volume (mL) = g/mL

Extensive Property depends upon mass


Examples: volume, heat
Intensive Property does not depend upon
mass

Examples: Color, Temperature, boiling
temperature, etc.
Physical & Chemical Changes
Physical & Chemical Changes
Uncertainty in Measurement

Precision


Reproducible
Accuracy

Correct and Reproducible
How are they different?
Precision means reproducible & may be correct or
incorrect
Significant Figures
1.
2.
3.
Left most nonzero digit is the most
significant figure (MSF).
When there is a decimal point, the right
most digit is the least significant figure
(LSF).
The number of digits from the MSF to the
LSF is the number of significant figures.
12.3100
MSF LSF
(6 significant figures)
1234 = 1 .234 x 103
*no decimal point
MSF LSF
(4 significant figures)
1200
=
1.2 x 103
1.20 x 103
1.200 x 103
(2 significant figures)
(3 significant figures)
(4 significant
=
5.20 x 10-3
(3 significant figures)
figures)
0.00520
Exact Numbers
12 inches = 1 foot
12.000000…
(∞ significant figures)
Rules of Multiplication & Division
Go by minimum number of significant figures
1.0 x
5.3642
=
5.3642

2 sig.
fig.
5 sig.
fig.
Drop and round off
=

5.4
Round off rule


When dropping a digit greater than 5, add 1 to the
preceeding digit.
When dropping a digit equal to 5, add 1 for odd
preceeding digit; otherwise, do not add.
Rule of Addition & Subtraction

Go by minimum number of decimal places
(dp).
0.1
1 dp
+
22.32 =
2 dp
=
Dimensional Analysis
Problems
22.42
drop
22.4