Section 3.2 through 3.4 Lecture for Honors & Prep Chemistry

1. Bellwork- sig figs Honors only
For full credit you must…
How many sig figs?
1) 1000g 6) 1000g = 1kg
2) 1000.0g 7) 1000 people
3) 0.000110g 8) 1.1m + 11.11m +1.111m =
4) 1.1 x 10-4g 9) 11m x 101m =
5) 10,101g

2. Lecture 3.2- Units

3. 3.1 Using and Expressing
Measurements
A measurement is a quantity that
has both a number and a unit.

4. Measuring with SI Units
5 of the 7 S.I. base units are used by
chemists
m meter (length)
kg kilogram (mass)
K kelvin (temperature)
s second (time)
mol mole (quantity)

5. 3.2 Units and Quantities
For very large or very small
measurements, use a metric prefix.

6. 3.2 Units and Quantities

7. Units of Volume
3.2 Units and Quantities
The SI unit of volume is the cubic meter (m)3,
which is the amount of space occupied by a
cube that is 1 m along each edge.
A more convenient unit of volume for
everyday use is the liter, a non-SI unit.

8. Units of Volume
3.2 Units and Quantities
The SI unit of volume is the cubic meter (m)3,
which is the amount of space occupied by a
cube that is 1 m along each edge.
A more convenient unit of volume for
everyday use is the liter, a non-SI unit.
A liter (L) is the volume of a cube
that is 10 centimeters (10 cm)
along each edge.
10 cm × 10 cm × 10 cm = 1000 cm3 = 1 L

9. 3.2 Units and Quantities
Common metric units of volume
include the liter, milliliter (aka cubic
centimeter), and microliter.

10. 3.2 Units and Quantities
Common metric units of mass
include kilogram, gram, milligram,
and microgram.

11. 3.2 Units and Quantities
Scientists commonly use two
equivalent units of temperature,
the degree Celsius and the kelvin.

12. Absolute zero =
lowest possible
temperature

13. 3.2 Units and Quantities
1 C° = 1 K

16. 3.2 Units and Quantities

17. 3.2 Units and Quantities
Energy is the capacity to do
work or to produce heat.

18. 3.2 Units and Quantities
The joule (J) is the SI unit of
energy.
One calorie (cal) is the quantity
of heat that raises the
temperature of 1 g of pure water

19. BELLWORK- units
Student’s Magnitude SI unit
1)Match the
age 1.6 K appropriate
Body 6.2 x 101 kg magnitude and
temp.
SI unit to the
height 3.1 x 102 m item being
mass 4.8 x 108 s measured.
2)Convert 32°C to Kelvins
3)Convert 250K to °C
4) Convert $9,675,000,000,000 to scientific notation.
5) Convert 1.2x10-7m to standard notation

20. Lecture 3.3- Unit conversions

21. A3.3
conversion factor is a fraction that
is equal to one because the values
in the numerator and the
denominator are equal.
Ex. 1g and 1000mg
1000mg 1g

22. A3.3
conversion factor is a fraction that
is equal to one because the values
in the numerator and the
denominator are equal.
Ex. 1g and 1000mg
1000mg 1g

23. A3.3
conversion factor is a fraction that
is equal to one because the values
in the numerator and the
denominator are equal.
Ex. 1g and 1000mg
1000mg 1g

24. A3.3
conversion factor is a fraction that
is equal to one because the values
in the numerator and the
denominator are equal.
Ex. 1g and 1000mg
1000mg 1g

25. A3.3
conversion factor is a fraction that
is equal to one because the values
in the numerator and the
denominator are equal.
Ex. 1g and 1000mg
1000mg 1g

26. A3.3
conversion factor is a fraction that
is equal to one because the values
in the numerator and the
denominator are equal.
Ex. 1g and 1000mg
1000mg 1g

27. 3.3 Conversion Factors
Using the relationship 1000mL = 1L,
you can write the following
conversion factors.
1000 ml 1L
1L 1000ml

28. 3.3
Using conversion factors to change units
5,600ml

29. 3.3
Using conversion factors to change units
Put the units you’ve got on the bottom, so
they will cancel out.
Put the units you want on the top.
5,600ml x 1L
1000ml

30. 3.3
Using conversion factors to change units
Put the units you’ve got on the bottom, so
they will cancel out.
Put the units you want on the top.
5,600ml x 1L = 5.6L
1000ml

31. 3.3
Using conversion factors to change units
Put the units you’ve got on the bottom, so
they will cancel out.
Put the units you want on the top.
5,600ml x 1L = 5.6L
1000ml
Because 1 L=1000ml we are really
just multiplying by one and
THE VALUE STAYS THE SAME.

32. 3.5
Using multiple conversion factors in
a row is called dimensional analysis

33. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
8 hours
GIVEN

34. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
8 hours ? seconds
GIVEN WANTED

35. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
How do I get
8 hours ? seconds
GIVEN in between? WANTED

36. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
?
8 hours
seconds

37. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
60 minutes ?
8 hours x
1 hour seconds

38. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
60 minutes x 60 seconds ?
8 hours x =
1 hour 1minute seconds

39. 3.5
Using multiple conversion factors in
a row is called dimensional analysis
60 minutes x 60 seconds ?
8 hours x =
1 hour 1minute seconds
8 x 60 x 60 = 28,800 seconds

40. for Sample Problem 3.7
PRACTICE!
CONVERT
5670 milliseconds to seconds
CONVERT
100 km/h to m/s

41. Lecture 3.4- Density

42. 3.4 Determining Density
Density is the ratio of the mass of
an object to its volume.

43. 3.4 Determining Density
Each of these 10-g samples has a
different volume because the
densities vary.

44. 3.4 Determining Density
Density is an intensive property
that depends only on the
composition of a substance, not
on the size of the sample.

45. 3.4 Determining Density
The density of corn oil is less
than the density of corn
syrup. For that reason, the oil
floats on top of the syrup.
HIGH DENSITY on bottom
LOW DENSITY on top

46. 3.4 Density and Temperature

47. 3.4 Density and Temperature
The volume of most substances
increases as the temperature increases.
The mass remains the same.
The density of most
substances will decrease as the
temperature increases.

49. 3.10

50. 3.10

51. 3.10

52. 3.11

53. 3.11

54. 3.11

55. 3.11

56. 3.3 Section Quiz
Express the density 5.6 g/cm3 in kg/m3.
a) 5.6 × 106kg/m3
b) 5.6 × 103kg/m3
c) 0.56 kg/m3
d) 0.0056 kg/m3

57. 3.3 Section Quiz
Express the density 5.6 g/cm3 in kg/m3.
a) 5.6 × 106kg/m3
b) 5.6 × 103kg/m3
c) 0.56 kg/m3
d) 0.0056 kg/m3