MSC 180 Water Analysis

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MSC 180 - Water Analysis

• Instructor Jacqui Jenkins
• Office S204D
• Email jjenkins_at_cfcc.edu
• Phone [phone]

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Laboratory Safety

• Safety Requirements

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Safety Equipment

• Eyewash Shower
• First Aid Kit

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Fire Fire Safety

• Fire Blanket
• Fire Extinguisher
• Water
• CO2
• Dry-Powder
• Halon

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Safety Equipment

• MSDS
• Material Safety Data Sheets

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The Metric System

• Decimal system of measurement
• Base of 10
• History
• France, 1791
• Adopted by scientists throughout that world, 1960
• International System (le Système International)
• SI
• US, Liberia, and Myanmar (Burma)
• Adoption of Metric system in the US

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The Metric System

• Length
• Meter
• Mass
• Kilogram
• Volume
• Liter

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The Metric System - Prefixes

• micro µ one-millionth 10-6
• milli m one-thousandth 10-3
• centi c one-hundredth 10-2
• deci d one-tenth 10-1
• deka dk ten times 101
• hecto h hundred times 102
• kilo k thousand times 103
• mega M million times 106

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The Metric System - Length

• 1 micrometer (µm) 0.000001 meter
• 1 millimeter (mm) 0.001 meter
• 1 centimeter (cm) 0.01 meter
• 1 decimeter (dm) 0.1 meter
• 1 dekameter (dkm) 10 meters
• 1 hectometer (hm) 100 meters
• 1 kilometer (km) 1000 meters

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The Metric System Weight (Mass)

• 1 microgram (µg) 0.000001 gram
• 1 milligram (mg) 0.001 gram
• 1 centigram (cg) 0.01 gram
• 1 decigram (dg) 0.1 gram
• 1 dekagram (dkg) 10 grams
• 1 hectogram (hg) 100 grams
• 1 kilogram (kg) 1000 grams

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The Metric System - Volume

• 1 microliter (µL) 0.000001 liter
• 1 milliliter (mL) 0.001 liter
• 1 centiliter (cL) 0.01 liter
• 1 deciliter (dL) 0.1 liter
• 1 dekaliter (dkL) 10 liters
• 1 hectoliter (hL) 100 liters
• 1 kiloliter (kL) 1000 liters

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• 10 millipedes 1 centipede
• 3 1/3 tridents 1 decadent
• 10 monologs 5 dialogues
• 2 monograms 1 diagram
• 8 nickels 2 paradigms
• 2 snake eyes 1 paradise
• 2 wharves 1 paradox
• 106 phones 1 microphone
• 106 phones 1 megaphone
• 102 mental 1 centimental
• 101 mate 1 decimate
• 1012 boos 1 picoboo

• 1012 microphones 1 megaphone
• 106 bicycles 2 megacycles
• 2000 mockingbirds 2 kilomockingbirds
• 10 cards 1 decacards
• 106 fish 1 microfiche
• 454 graham crackers 1 pound cake
• 1012 pins 1 terrapin
• 10 rations 1 decoration

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The Metric System

• Temperature
• Celsius (C)
• Kelvin (K)
• Absolute zero
• 0 K
• -273.15 C
• -459.67 ?F

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Conversion

• Dimensional Analysis
• Factor-Label Method

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Conversion

• Metric English Equivalents
• 1 cm 0.3937 in.
• 1 m 3.281 ft 39.37 in.
• 1 km 0.6214 mile
• 1 L 0.2646 gal
• 1 kg 2.204 lbs

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Conversion

• K C 273
• C 5/9(F - 32)
• F 9/5(C 32)

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The Metric System

• Density
• Mass per unit volume
• D M/V
• Mass in grams
• Volume in cubic centimeters
• g/cm3

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Lab Procedures

• Precision
• 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

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Significant Figures

• The 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.

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Significant Figures

• Cardinal Rule
• A final result should never contain any more
  significant figures than the least precise data
  used to calculate it.

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Significant Figures

• General Rules
• The concept applies only to measured quantities.
• All significant figures are counted from the
  first nonzero digit.
• All confined zeros in a number are significant.
• Zeros that are both to the right of the decimal
  point and to the right of nonzero digits are
  significant.
• The answer in an addition or subtraction problem
  must be rounded off to the first column that has
  a doubtful digit.

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Rounding

• If 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.

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Rounding

• Rules 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
• If the digit following the last significant
  figure is exactly 5, the number is rounded off to
  the nearest even digit

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Labware

• Section 2 of the handbook
• These will be displayed for the rest of the week,
  then returned to their respective places for the
  rest of the semester
• What is it?
• What is it used for?

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Lab Procedures

• Recording Data/Lab Notebooks
• Ink
• Never rip out pages
• Never erase data cross out mistakes
• Record all information, no matter how trivial
• Be specific
• Check all calculations
• And, obviously, BE NEAT

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Lab Procedures

• Weighing/Balances
• Most important tool in a chemistry lab
• Used to determine the mass of an object
• Triple-beam balance
• Analytical balance