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)

SI Prefixes Common to Chemistry Unit Abbr. Exponent Kilo k 103 Deci d 10-1 Centi c 10-2 Milli m 10-3 Micro  10-6

Metric Conversions g m L 103 102 101 10-1 10-2 10-3 kilo hecto deka Base unit deci centi milli 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 Conversions g m L 103 102 101 10-1 10-2 10-3 kilo hecto deka Base unit deci centi milli 1 2 3 18 L 18 liters = 18 000 milliliters Example #1: Convert 18 liters to milliliters

Metric Conversions g m L 103 102 101 10-1 10-2 10-3 kilo hecto deka Base unit deci centi milli 3 2 1 450 mg = 0.450 g 450 mg Example #2: Convert 450 milligrams to grams

Metric Conversions g m L 103 102 101 10-1 10-2 10-3 kilo hecto deka Base unit deci centi milli 1 2 3 4 5 6 20 kg 20 kg = 20 000 000 mg Example #3: Convert 20 kilograms to milligrams

Metric Conversion Practice-Dimensional Analysis Decimal Ladder

DA format Given unit always goes first new unit = Given unit new unit

Problem #1 Convert 400 mL to Liters 400 mL 1 L .400 L = 1 000 mL = 4x10-1 L

Problem #2 Convert 10 meters to mm 10 m 1 000 mm 10 000 mm = 1 m = 1x104 mm

Problem #3 Convert 73 grams to kg 73 g 1 kg 0.073 kg = 1 000 g = 7.3x10-2 kg

M Convert 0.02 kilometers to m 0.02 km 1 000 m 20 m = 1 km = 2x101 m

4 Convert 20 centimeters to m 20 cm 1 m 0.20 m = 100 cm = 2x10-1 m

2 Convert 450 milliliters to dL 450 mL 1 dL 4.5 dL = 100 mL

1 Convert 10 kilograms to grams 10 kg 1 000 g 10 000 g = 1 kg = 1x104 g

Temperature Change KoC (-273) oCK (+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 55.85 1 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 55.85 1

Problem #7 Convert 54g Na to mol Na 1 mol Na 54 g Na 2.4 = 23 g Na

Problem #8 6.3 mol Al to g Al 26.98 g Al = 1 mol Al 6.3 mol Al 170

Problem #10 Convert 175 mL to cm3 1 cm3 175 mL 175 cm3 = 1 mL = 1.75x102 cm3