Drill: Classify each:•Filtered Sea water
•Orange juice
•Mercury
•Salt
•Pure ice water
Review Drill,Grade HW & Collect Both
CHM II HW•Review PPs 1 – 4
•Work the attached assignment & turn it in tomorrow.
Accuracy•How close you are
to the real answer
Precision•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
0
1
2
3
BuretteMeasurements
Eachmeasurementshould have2 decimals
Solve thecorrectreading for thevolumein theburette
0
1
2
3
BuretteMeasurements
Eachmeasurementshould have2 decimals
~ 1.36
the lastdecimalwill haveuncertainty
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 10n
•M = 1.00 M < 10.00
•n = an integer
Basic Units•Length meters
•Mass kilograms
•Time seconds
•Temperature Kelvin
•Amount Chm Mole
•Current Ampere
•Luminous In Candela
MetricPrefixes
•Giga (G)
•Mega(M)
•Kilo(k) Nano(n)
•Milli(m)
•Micro() Centi(c)
MetricPrefixes
•(G) = 109
•(M) = 106
•(k) = 103 (n) = 10-9
•(m) = 10-3
•() = 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 g
Convert:2.50 cm 10-2m Mm
cm 106m
Convert:2.50 cm 10-2m Mm
cm 106m
= 2.50 x 10-8 Mm
Convert:4.2 ns 10-9s ms
ns 10-3s
Convert:4.2 ns 10-9s ms
ns 10-3s
= 4.2 x 10-6 ms
Convert:3.15 kg 103g g
kg 10-6g
Convert:3.15 kg 103g g
kg 10-6g
= 3.15 x 109g
Convert:4.35 kg/L to mg/L
2.31 mm/ns to cm/Ms
4.35 kg 103g mg 10-6L L kg 10-3g L
4.35 kg 103g mg 10-6L L kg 10-3g L
= 4.35 mg/L
2.31 mm 10-3 m cm ns mm 10-2 m
ns 106 s 10-9 s Ms
2.31 mm 10-3 m cm ns mm 10-2 m
ns 106 s 10-9 s Ms
= 2.31 x 1014 cm/Ms
Calculate the volume in m3 occupied by 750 kg of gas with
1.50 g/L1 cm3 = 1 mL
Calculate the mass in kg of a board that has
dimensions of 250 mm x 4.0 x 104 m x 2.5 m and
had a density of 0.80 g/mL1 ml = 1 cm3
Calculate the density in g/mL of a 3.14 x 103 kg cylinder that 5.0 m long & has a diameter of 2.0 m.
How many nm willan object travel in
1/132 ks at720 miles per hour
1 inch = 2.54 cm1 mile = 5280 ft
Determine the length in miles of a light year
• Light year = distance light travels in one year
• c = 3.0 x 108 m/s
• 1 mile = 5280 ft
• 1 inch = 2.54 cm