1. Chapter 2: Measurement and Problem Solving
16 days
Chapter 2: Measurement and Problem Solving

2. First day of school Lab safety
Day One
First day of school Lab safety

3. Syllabus HIGHLIGHTS!!! Expectations How do I get a good grade?
Be Prepared
NO FOOD OR DRINK IN THIS CLASSROOM EVER!!!
How do I get a good grade?
Hall Passes
Absences

4. MISCELLANEOUS
BOOKS: Put name in front cover and please cover the book!
Three ring binder
Calculator
Lab Safety Contract

5. Lab Notebook Labs Spiral bound notebook
Lab procedure: found online and in the room
Must be written in your lab notebook before you begin lab as well as any data tables you may need
Completed with a partner but must be a collaborative effort
Each partner is responsible to have the data before they leave the room

6. Lab Safety Video

7. Location of Safety Equipment
Goggles
Aprons
Sand
Eyewash station
Safety Shower
MSDS Sheets
Fire Blanket
Fire extinguisher
Emergency Stop Button
Fire Alarm
Fume hood
Broken Glass Container
Assignment: Draw a diagram of the room and label the safety equipment listed above.
Explain what each of the above is used for and when they are used.

8. Websites Measurements & Scientific Notation
Day Two
Websites Measurements & Scientific Notation

9. Two websites you will be using all year!!!
Class website
Lab manual
Calendar
Lecture Notes
Answer Keys to Homework
Additional Reviews and assignments

10. What Is a Measurement? Quantitative observation
Comparison to an agreed upon standard
Every measurement has a number and a unit

11. A Measurement
The unit tells you to what standard you are comparing your object.
The number tells you:
What multiple of the standard the object measures.
The uncertainty in the measurement.

12. Scientists have measured the average global temperature rise over the past century to be 0.6 °C
°C tells you that the temperature is being compared to the Celsius temperature scale.
0.6 tells you that:
The average temperature rise is 0.6 times the standard unit of 1 degree Celsius.
The confidence in the measurement is such that we are certain the measurement is between 0.5 and 0.7 °C.

13. Scientific Notation
We should all be familiar with this but I just want to remind you of a few things!!!
S.N. is an easy way to express VERY large or VERY small numbers
Chemistry most of the time deals with extremely small number considering we talk about atoms!

14. 3 parts to S.N. -9
1.2 10 X

15. How to Express a number in Scientific Notation
Move the decimal point to obtain a number between 1 and 10.
Write the result from Step 1 multiplied by 10 raised to the number of places you moved the decimal
** The exponent is POSITIVE if you moved the decimal to the LEFT
** The exponent if NEGATIVE if you moved the decimal to the RIGHT

16. Practice—Write the Following in Scientific Notation

17. Practice—Write the Following in Standard Form
2.1 x x x 10-2
4.02 x x x 100

18. Metric and Factor Label
Day Three
Metric and Factor Label

19. Metric System Group of units used to make any kind of measurements
Best known for its simpleness
Why is it so simple?
Used all around the world with scientists

20. The Standard Units
Scientists generally report results in an agreed upon International System.
The SI System
Aka Système International
Quantity
Unit
Symbol
Length
meter m
Mass
kilogram kg
Time
second s
Temperature
kelvin K

21. Some Standard Units in the Metric System
Quantity Measured
Name of Unit
Abbreviation
Mass
gram g
Length
meter m
Volume
liter L
Time
seconds s
Temperature
Kelvin K

22. King Henry Died By Drinking Chocolate Milk

23. Common Prefixes in the SI System
Symbol
Decimal
Equivalent
Power of 10
mega- M
1,000,000
Base x 106
kilo- k
1,000
Base x 103
deci- d
0.1
Base x 10-1
centi- c
0.01
Base x 10-2
milli- m
0.001
Base x 10-3
micro-
m or mc
Base x 10-6
nano- n
Base x 10-9
Tro's "Introductory Chemistry", Chapter 2

24. Let’s Try A Few 125 cm = ____________ mm 0.2568 L = _________ mL
2.56 kg = ________ g

25. Factor Label Dimensional Analysis
EASY way to convert from one unit to another unit!!
WE will be doing this ALL YEAR long! So you better pay attention now!
UNITS ARE EXTREMELY IMPORTANT

26. Units Always write every number with its associated unit.
Always include units in your calculations.
You can do the same kind of operations on units as you can with numbers.
cm × cm = cm2
cm + cm = cm
cm ÷ cm = 1
Using units as a guide to problem solving is called dimensional analysis.

27. Problem Solving and Dimensional Analysis
Many problems in chemistry involve using relationships to convert one unit of measurement to another.
Conversion factors are relationships between two units.
May be exact or measured.
Conversion factors generated from equivalence statements.
e.g., 1 inch = 2.54 cm can give or

28. Problem Solving and Dimensional Analysis, Continued
Arrange conversion factors so the starting unit cancels.
Arrange conversion factor so the starting unit is on the bottom of the conversion factor.
May string conversion factors.
So we do not need to know every relationship, as long as we can find something else the starting and desired units are related to :

29. Systematic Approach Write down the given amount and unit.
Write down what you want to find and unit.
3. Write down needed conversion factors or equations.

30. Common Units and Their Equivalents
Length
1 kilometer (km) =
mile (mi)
1 meter (m)
39.37 inches (in.)
1.094 yards (yd)
1 foot (ft)
30.48 centimeters (cm)
1 inch (in.)
2.54 centimeters (cm) exactly

31. Common Units and Their Equivalents, Continued
Mass
1 kilogram (km) =
2.205 pounds (lb)
1 pound (lb)
grams (g)
1 ounce (oz)
28.35 (g)
Volume
1 liter (L) =
1000 milliliters (mL)
1000 cubic centimeters (cm3)
1.057 quarts (qt)
1 U.S. gallon (gal)
3.785 liters (L)

32. Lets take a look at one!
I drive 20 miles to school every day. I want to know how many kilometers I drive.

33. Lets Try a Few 125 lb = ________ kg 2.5 gallons = ________ L
3.1 km = _________ miles

34. Significant Figures and Factor label
Day Four
Significant Figures and Factor label

35. Exact Numbers vs. Measurements
Sometimes you can determine an exact value for a quality of an object.
Often by counting.
Pennies in a pile.
Sometimes by definition
1 ounce is exactly 1/16th of 1 pound.
Whenever you use an instrument to compare a quality of an object to a standard, there is uncertainty in the comparison.

36. Reporting Measurements
Measurements are written to indicate the uncertainty in the measurement.
The system of writing measurements we use is called significant figures.
When writing measurements, all the digits written are known with certainty except the last one, which is an estimate.
45.872
Certain
Estimated
45.872

37. Skillbuilder 2.3—Reporting the Right Number of Digits
A thermometer used to measure the temperature of a backyard hot tub is shown to the right. What is the temperature reading to the correct number of digits?

38. Reporting Numbers with Sig. Figs
When we report numbers in this class we need to make sure that we do not report them more specific than they really are. WHAT???
Volume of a box
Length = 7.12 cm
Width = 2.15 cm
Height = 2.15 cm

39. How do I know if a number is significant?
All NONZERO digits are significant
Zeros between two nonzero numbers are significant
Trailing zeros are significant
Leading zeros are NOT significant, they are only place holders
5. Zeros at the end of a number but before a decimal are NOT significant

40. Lets try a few
0.0035
1.080
2371
2.97 x 105
100000
0.500
58.31

41. Factor Label (Multi-step)
I went to the Yukon last summer and the speed limit sign said 105 km/hr. What was the speed limit in mi/hr?

42. If I drive a total of 50 miles a day and my car gets 49 miles/gallon
If I drive a total of 50 miles a day and my car gets 49 miles/gallon. How much does it cost me a week to drive to work? Assuming price for gas is $2.50/gallon.

43. A circle has an area of 2,659 cm2. what is its area in square meters?

44. Significant Figures and Factor Label
Day Five
Significant Figures and Factor Label

45. Significant Figures in Calculations ADDITION AND SUBTRACTION
The difference and sum carries the same number of decimal places as the quantity carrying the FEWEST decimal places.
3.449 cm – 0.76 cm =
2.5 cm + 2 cm =

46. Significant Figures in Calculations (MULTIPLICATION AND DIVISION)
The results carries the same number of significant figures as the factor with the FEWEST figures.
5.892 cm X 6.10 cm =

47. Lets take a look back at our Volume of a Box!!
Length = 7.12 cm
Width = 2.15 cm
Height = 2.15 cm

48. Lets Try a Few! 1.01mm x 0.12 cm x 53.51 cm = 56.55 cm x 0.920 cm =
345.0 ml / 120 ml =

49. Significant Figures Lab
Day Six
Significant Figures Lab

50. Mastering Chemistry Website
Day Seven
Mastering Chemistry Website

51. Day Eight
Density

52. Density Ratio of its mass to volume
“How much stuff is in a given space”
Differs from one substance to another

53. How do I calculate DENSITY?
What about the units?

54. I have a sample of platinum that has a mass of 5
I have a sample of platinum that has a mass of 5.84g and it displaces cm3 of water. What is the density?

55. Lets Try a Few!
The gasoline in an automobile gas tank has a mass of 60.0 kg and a density of 0.752g /cm3. What is its volume in ml?
A steel cylinder has a volume of 246 cm3 and a density of 7.93 g/cm3. What is its mass in kg?

56. Day Nine
Density Day 2

57. Measurement and Density Lab (Sig. Figs. Lab)
Day Ten and Eleven
Measurement and Density Lab (Sig. Figs. Lab)

58. Day Twelve
Practice Test

59. Day Thirteen
review

60. Day Fourteen
Test