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The SI System of Measurement. The Nature of Measurement. A Measurement is a quantitative observation consisting of TWO parts. Part 1 - number Part 2 - scale (unit) Examples: 20 grams 6.63 x 10 -34 Joule·seconds. The Fundamental SI Units (le Système International, SI). - PowerPoint PPT Presentation
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The SI System of Measurement
The Nature of Measurement
Part 1 - numberPart 2 - scale (unit)
Examples:20 grams
6.63 x 10-34 Joule·seconds
A Measurement is a quantitative observation consisting of TWO parts
The Fundamental SI Units (le Système International, SI)
Physical Quantity Name Abbreviation
Mass kilogram kg
Length meter m
Time second s
Temperature Kelvin K
Electric Current Ampere A
Amount of Substance mole mol
Luminous I ntensity candela cd
SI PrefixesCommon to Chemistry
Prefix Unit Abbr. ExponentKilo k 103
Deci d 10-1
Centi c 10-2
Milli m 10-3
Micro 10-6
Metric ConversionsgmL 10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Conversions in the metric system are merely a matter of moving a decimal point. The “base unit” means the you have a quantity (grams, meters, Liters, etc without a prefix.
Metric ConversionsgmL 10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Example #1: Convert 18 liters to milliliters
18 L1 2 3
18 liters = 18 000 milliliters
Metric ConversionsgmL 10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Example #2: Convert 450 milligrams to grams
123450 mg450 mg = 0.450 g
Metric ConversionsgmL 10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Example #3: Convert 20 kilograms to milligrams
20 kg1 2 3 4 5 6
20 kg = 20 000 000 mg
Metric Conversion Practice-
Dimensional Analysis
Decimal Ladder
DA formatGiven unit always goes first
Given unit
=Given unit
new unit new unit
Problem #1Convert 400 mL to Liters
400 mL= L
mL
L
1 000
1 .400
= 0.4 L
= 4x10-1 L
Problem #2Convert 10 meters to mm
10 m= m
mm
mm
1
1 000 10 000
= 1x104 mm
Problem #3Convert 73 grams to kg
73 g= kg
g
kg
1 000
1 0.073
= 7.3x10-2 kg
MConvert 0.02 kilometers to m
0.02 km= m
km
m
1
1 000 20
= 2x101 m
4Convert 20 centimeters to m
20 cm= m
cm
m
100
1 0.20
= 2x10-1 m
2Convert 450 milliliters to dL
450 mL= dL
mL
dL
100
1 4.5
1Convert 10 kilograms to grams
10 kg= g
kg
g
1
1 000 10 000
= 1x104 g
Temperature Change
KoC (-273)oCK (+273)
Problem #5
Convert 45oC to K
45 oC +273 =318K
Problem #6
Convert K to oC
746K-273 =473K
Molar Conversions
Mole-the amount of a substance• 1 mol of any substance equals
6.022x1023 particles– atoms– molecules
Take a look at the Periodic Table of Elements• 1 mol of Na is 22.99 g• 1 mol of H20 is 18.02g
Molar Mass
The amount of matter in 1 mole• 10.81 g B in 1 mol B• 58.69 g Ni in 1 mol Ni• ______ g Fe in 1 mol Fe• 12.01 g C in ___ mol C
55.851
Problem #7Convert 54g Na to mol Na
54 g Na= mol
Nag Na
mol Na23
12.4
Problem #86.3 mol Al to g Al
6.3 mol Al= g Al
mol Al
g Al
1
26.98 170
Problem #10Convert 175 mL to cm3
175 mL= cm3
mL
cm3
1
1175
= 1.75x102 cm3