Drill: Classify each:
•Filtered Sea water
•Orange juice
•Mercury
•Salt
•Pure ice water

CHM II HW
•Review PPs 1 – 4
•Work the attached assignment & turn it in tomorrow.

•How well one can repeat his or her work
•Repeatability

Uncertainty
•All measurements have a degree of unreliability
•Usually in the last digit of a measurement

Burette
Measurements
Each measurement should have
2 decimals
3
0
1
2
Solve the correct reading for the volume in the burette

Burette
Measurements
Each measurement should have
2 decimals
3
0
~ 1.36
the last
1 decimal will have
2 uncertainty

Significant Digits
•Meaningful digits in a number

Determining Significance
• All non-zero digits
• All zeros between non-zero numbers
• All trailing zeros if there is a decimal place

Multiplication Uncertainty
• The answer should have the same number of significant digits as the multiplier with the least number of SD
• Same for division

Addition Uncertainty
• When adding, line up decimal place & add
• The decimal places in the answer should = the least
• Same for subtraction

Scientific Notation
•M x 10 n
•M = 1.00 
M < 10.00
•n = an integer

•Length meters
•Mass kilograms
•Time seconds

•Temperature Kelvin
•Amount Chm
Mole
•Current
Ampere
•Luminous In Candela

•Giga (G)
•Mega(M)
•Kilo(k)
Metric
Prefixes
Nano(n)
•Milli(m)
•Micro( m
) Centi(c)

•(G) = 10 9 Metric
•(M) = 10 6 Prefixes
•(k) = 10 3 (n) = 10 -9
•(m) = 10 -3
•( m
) = 10 -6 (c) = 10 -2

Conversion Factor
• Ratio equal to one
• 12 inches/1 foot = 1
• Multiply one unit by a conversion to obtain another unit w/o affecting magnitude

Convert 40.0 ft to inches
40.0 ft 12 in ft
=

Convert 40.0 ft to inches
40.0 ft 12 in ft
=
480 inches

Convert:
•2.50 cm to Mm
•4.2 ns to ms
•3.15 kg to m g

Convert:
2.50 cm 10 -2 m Mm cm 10 6 m

Convert:
2.50 cm 10 -2 m Mm cm 10 6 m
= 2.50 x 10 -8 Mm

Convert:
4.2 ns 10 -9 s ms ns 10 -3 s

Convert:
4.2 ns 10 -9 s ms ns 10 -3 s
= 4.2 x 10 -6 ms

Convert:
3.15 kg 10 3 g m g kg 10 -6 g

Convert:
3.15 kg 10 3 g m g kg 10 -6 g
= 3.15 x 10 9 m g

4.35 kg/L to mg/ m
L
2.31 mm/ns to cm/Ms

4.35 kg 10 3 g mg 10 -6 L
L kg 10 -3 g m
L

4.35 kg 10 3 g mg 10 -6 L
L kg 10 -3 g m
L
= 4.35 mg/ m
L

2.31 mm 10 -3 m cm ns mm 10 -2 m ns 10 6 s
10 -9 s Ms

2.31 mm 10 -3 m cm ns mm 10 -2 m ns 10 6 s
10 -9 s Ms

= 2.31 x 10 14 cm/Ms

Calculate the volume in m 3 occupied by
750 kg of gas with
1.50 g/L
1 cm 3 = 1 mL

Calculate the mass in kg of a board that has dimensions of 250 mm x
4.0 x 10 4 m m x 2.5 m and had a density of 0.80 g/mL
1 ml = 1 cm 3

Calculate the density in g/mL of a 3.14 x
10 3 kg cylinder that
5.0 m long & has a diameter of 2.0 m.

How many nm will an object travel in
1/132 ks at
720 miles per hour
1 inch = 2.54 cm
1 mile = 5280 ft

Determine the length in miles of a light year
• Light year = distance light travels in one year
• c = 3.0 x 10 8 m/s
• 1 mile = 5280 ft
• 1 inch = 2.54 cm