Chem 15 | Chemistry for Engineers
Lecture 1: Chemistry and
Engineering
“All engineering designs involve
MATTER”
Chem 15 | Chemistry for Engineers
Chemistry?
The study of MATTER:
- its composition
- changes that matter undergoes
Matter is anything that occupies space and has
mass.
“Therefore, MATTER is EVERYTHING around us!”
Chem 15 | Chemistry for Engineers
Why study chemistry?
Chemistry is the CENTRAL SCIENCE
|Biochemistry
|Energy
The flash of the firefly
results from a chemical
reaction in the insect
Solar panels are
composed of specially
treated silicon
|Technology
|Medicine
LEDs (light emitting
diodes) are formed
from elements such
as gallium, arsenic,
and phosphorus
Connectors and tubing for
medical procedures
such as intravenous
injections are made
from plastics highly
resistant to chemical
attack
Chem 15 | Chemistry for Engineers
3 Levels in Understanding
Chemistry
1. The Macroscopic Perspective
Chem 15 | Chemistry for Engineers
3 Levels in Understanding
Chemistry
1. The Macroscopic Perspective:
Chem 15 | Chemistry for Engineers
1. The Macroscopic Perspective:
physical and chemical properties
Chem 15 | Chemistry for Engineers
Physical or Chemical change?
Chem 15 | Chemistry for Engineers
3 Levels in Understanding
Chemistry
2. The Microscopic/Particulate Perspective:
ATOM
ELEMENTS
Chem 15 | Chemistry for Engineers
Chem 15 | Chemistry for Engineers
3 Levels in Understanding
Chemistry
3. Symbolic Representation:
Using chemical formulas and structures
Chemical Formula
Chem 15 | Chemistry for Engineers
Chemical Structure
Scientific Method
Chem 15 | Chemistry for Engineers
Precision and Accuracy
Precision
- how closely individual measurements to agree with
one another
Accuracy
- how closely individual measurements agree with the
correct “true” value
Chem 15 | Chemistry for Engineers
Numbers and Measurements
Chem 15 | Chemistry for Engineers
Chem 15 | Chemistry for Engineers
Temperature Scales
Chem 15 | Chemistry for Engineers
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.
Chem 15 | Chemistry for Engineers
Significant Figures
1. All non-zero number is significant.
2. Zeros between non-zero numbers are
significant.
3. Zeros before a non-zero number (with or
without a decimal) is not significant.
4. Zeros after a non-zero numbers in a decimal
is significant.
5. Zeros after a non-zero without decimal
points MAY or MAY NOT be significant.
Chem 15 | Chemistry for Engineers
Dimensional Analysis
Units are multiplied together or divided into each
other along with the numerical values.
Keep track of both numerical values and units.
Chem 15 | Chemistry for Engineers
Conversions
The density of Ti is 4.50 g/cm3. What is the
volume of 7.20 g Ti?
Chem 15 | Chemistry for Engineers
Using Unit Conversions
Express a volume of 1.250 L in mL, cm3, and m3.
Chem 15 | Chemistry for Engineers
Chem 15 | Chemistry for Engineers