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CHEMISTRY 104
CHAPTER 1: MATTER, MEASUREMENT, CALCULATIONS
Homework problems: 17, 19, 21, 23, 25, 29, 33, 37, 41, 45, 57, 65, 69, 73, 75, 77, 83
(at the end of the chapter, designated 1.17, 1.19, etc)
Outline
I.
II.
III.
IV.
Matter
A. Has mass, occupies space
B. Physical vs. chemical properties
C. Physical vs. chemical changes
Measurements
A. Scientific Notation (exponential notation)
B. Count vs Measurement
C. Counts or Definitions are not measurements – no uncertainty
1. Definitions not the same as conversion factors
2. Definition: 1 foot = 12 inches, 16 oz = 1 pound
3. Conversion factor 1 inch = 2.54... cm, 1 pound = 454.... g
D. Measurements have uncertainty
1.
Include all known digits plus one estimate digit
2. Significant figures
a. nonzero digits: always significant
123.41
(5 sig. figs.)
b. enclosed zeros: always significant
130.053
(6 sig. figs.)
c. leading zeroes: never significant
0.0000403
(3 sig. figs.)
d. trailing zeroes:
i.
after decimal: always significant
2.3400
(5 sig. figs.)
ii.
before decimal: can’t tell so assume not significant
2300
(2 sig. figs.)
E. Measurements have units
1. SI system
2. Metric system
a. Liter not SI but used very frequently
b. 1 cc = 1 mL
3. Derived Units (area, volume, etc.)
4. conversion factors (factor label, unit analysis, factor conversion method)
5. density and specific gravity
Temperature and Energy
A. Kinetic and Potential Energy
B. Temperature: Fahrenheit, Celsius, and Kelvin
C. Heat: the Joule, calorie and Calorie
D. Specific heat
1. Q = smΔT
Significant Figures Revisited
VI.
A. All digits known to be correct plus one uncertain
B. Always estimate between the smallest division when measuring
C. Addition
D. Multiplication
E. Plugging numbers into a calculator does NOT make them more or less accurate
More Calculations
A. Percent Calculations
B. Density
C. Unit conversions
D. How to approach word problems
1. Read the problem through once. Just read it – don’t try to solve it in 1 step
2. Determine what the questions is asking – this is usually at the end right
before the question mark.
3. Inventory your available information – what info do you have?
4. Plan how to get from what you have to what the question is asking
5. Set up the problem according to your plan map
6. do unit analysis (factor label method)
7. check for sig figs
8. plug numbers into calculator
Chapter Objectives
Knowledge
Recognize the SI units and its abbreviation (g and m) for mass and distance.
Memorize the prefixes mega-, kilo, centi-, milli-, and microMemorize formula for density (D = m/V) and specific heat (Q = smΔT)
Recall what specific gravity is
Comprehension
Use scientific notation to show correct number of significant figures
Understand the difference between chemical and physical changes, and between chemical
and physical properties
Application
Do calculations (addition/subtraction and multiplication/division) using the
correct number of significant figures
Analysis
Demonstrate the ability to do dimensional analysis with any conversion factors
Convert freely between the K, F, and C temperature scales
Given any two of density, mass, and volume, be able to find the third
Use the specific formula to calculate the missing element given the other three