MSC 180 – Water AnalysisMSC 180 – Water AnalysisInstructor: Jacqui Jenkins DeganOffice Hours: Tuesday & Thursday1300-1500
Friday0800-0850
Safety EquipmentSafety EquipmentEyewash & ShowerFirst Aid Kit
Fire & Fire SafetyFire & Fire SafetyFire BlanketFire Extinguisher
◦Water◦CO2
◦Dry-Powder◦Halon
Safety EquipmentSafety EquipmentMSDS
◦Material Safety Data Sheets
The Metric SystemThe Metric SystemDecimal system of measurementBase of 10History
◦France, 1791◦Adopted by scientists throughout the
world, 1960◦International System (le Système
International) SI
Calculation ErrorsCalculation ErrorsGimli Glider
Mars Climate Orbiter
Medical Mishaps
The Metric SystemThe Metric System
BASE UNITSMeterKilogramSecondKelvinMoleAmpereCandela
10n Prefix Decimal Articulation1024 yota- 1 000 000 000 000 000 000 000 000 Septillion1021 zeta- 1 000 000 000 000 000 000 000 Sextillion1018 exa- 1 000 000 000 000 000 000 Quintillion1015 peta- 1 000 000 000 000 000 Quadrillion1012 tera- 1 000 000 000 000 Trillion109 giga- 1 000 000 000 Billion106 mega- 1 000 000 Million103 kilo- 1 000 Thousand102 hecta- 100 Hundred101 deca- 10 Ten100 ---------- 1 One10-1 deci- 0.1 Tenth10-2 centi- 0.01 Hundredth10-3 milli- 0.001 Thousandth10-6 micro- 0.000 001 Millionth10-9 nano- 0.000 000 001 Billionth10-12 pico- 0.000 000 000 001 Trillionth10-15 femto- 0.000 000 000 000 001 Quadrillionth10-18 atto- 0.000 000 000 000 000 001 Quintillionth10-21 zepto- 0.000 000 000 000 000 000 001 Sextillionth10-24 yocto- 0.000 000 000 000 000 000 000 001 Septillionth
The Metric System - The Metric System - LengthLength1 micrometer (µm) = 0.000001
meter1 millimeter (mm) = 0.001 meter1 centimeter (cm) = 0.01 meter1 decimeter (dm) = 0.1 meter1 dekameter (dkm) = 10 meters1 hectometer (hm) = 100 meters1 kilometer (km) = 1000 meters
The Metric System – Weight The Metric System – Weight (Mass)(Mass)1 microgram (µg) = 0.000001 gram1 milligram (mg) = 0.001 gram1 centigram (cg) = 0.01 gram1 decigram (dg) = 0.1 gram1 dekagram (dkg) = 10 grams1 hectogram (hg) = 100 grams1 kilogram (kg) = 1000 grams
The Metric SystemThe Metric SystemTemperature
◦Celsius (°C)◦kelvin (K)
Absolute zero◦0 K◦-273.15 °C◦-459.67 F
Step Mental Arithmetic
1. Add 40 100 + 40 = 140
2. Multiply by 2 2 x 140 = 280
3. Subtract 10% 280 – 28 = 252
4. Subtract 40 to obtain final answer
252 – 40 = 212 degrees Fahrenheit
K = °C + 273°C = 5/9(°F -
32)°F = (9/5x°C)
+32 Step Mental Arithmetic
1. Add 40 32 + 40 = 72
2. Multiply by 0.5
0.5 x 72 = 36
3. Add 10% 36 – 3.6 = ~40
4. Subtract 40 to obtain final answer
40 – 40 = degrees Celsius
ConversionConversionDimensional Analysis
◦Factor-Label Method
← Conversion to English Units Conversion to SI Units →
English Units ←Divide by Multiply by→ SI Units
Length
Inches (in) 25.4 Millimeters (mm)Feet (ft) 0.305 Meters (m)
Yards (yd) 0.914 Meters (m)Miles (mi) 1.61 Kilometers (km)
Area
Square Inches (in2) 645.2 Square Millimeters (mm2)Square Feet (ft2) 0.093 Square Meters (m2)Square Yard (yd2) 0.836 Square Meters (m2)Square Miles (mi2) 2.59 Square Kilometers (km2)
Volume
Fluid Ounces (fl oz) 29.57 Milliliters (mL)Gallon (gal) 3.785 Liters (L)
Cubic Feet (ft3) 0.028 Cubic Meters (m3)Cubic Yard (yd3) 0.765 Cubic Meter (m3)
Note: All volumes greater than 1000 Liters should be in Cubic Meters (m3)Mass
Ounces (oz) 28.35 Grams (g)Drams (ℨ) 4.0 Grams (g)Grains (G) 0.0667 Grams (g)
Pounds (lb) 0.4536 Kilograms (kg)Short Ton (T) – 2000 lb 1016.05 Metric Ton/Megagrams (t/Mg)Short Ton (T) – 2000 lb 907.185 Kilograms (kg)
Temperature
Fahrenheit (°F) ← (1.8×°C)+32 (°F-32)/1.8 → Celsius (°C)Celsius (°C) °C + 273.15 Kelvin
Illumination
Lamberts (L) 0.3183 Candela per Square Meter (cd/cm2)
The Metric SystemThe Metric SystemDensity
◦Mass per unit volume◦D = m/V◦Mass in grams◦Volume in cubic centimeters
◦g/cm3
Lab ProceduresLab ProceduresPrecision
◦ Reproducibility◦ Check by
repeated measurements
◦ Poor precision results from poor techniques
Accuracy◦ Correctness◦ Check by using a
different method◦ Poor accuracy
results from procedural or equipment flaws
Significant FiguresSignificant FiguresThe precision of an instrument
reflects the number of significant figures in a reading◦Micro-balance versus bathroom scale
The number of significant figures in a lab measurement is the number of digits that are known accurately, plus one that is uncertain or doubtful.
Significant FiguresSignificant FiguresCardinal Rule:
◦A final result should never contain any more significant figures than the least precise data used to calculate it.
Significant FiguresSignificant Figures
General Rules:The concept applies only to
measured quantities.
Adding & Subtracting:◦Decimal places are important:
500.5 + 37.222 = 537.722Sig figs = 537.7
Multiplying & Dividing:◦Total significant figures are important:
15.41 x 3.2 = 49.312Sig figs = 49
RoundingRoundingIf a calculation yields a result
that would suggest more precision than the measurement from which it originated, rounding off to the proper number of significant figures is required.
RoundingRoundingRules of Rounding:
◦If the digit following the last significant figure is greater than 5, the number is rounded up to the next higher digit
◦If the digit following the last significant figure is less than 5, the number is rounded off to the present value of the last significant figure
◦When the digit is exactly 5, look to the digit preceding the 5: If the preceding digit is odd, round up. If the preceding digit is even, round down.
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