Transcript MSC 180 - Water Analysis

MSC 180 - Water Analysis
Instructor: Jacqui Jenkins
Office: S204D
Email: [email protected]
Phone: 362-7405
Laboratory Safety
 Safety Requirements
Safety Equipment
 Eyewash & Shower
 First Aid Kit
Fire & Fire Safety
 Fire Blanket
 Fire Extinguisher
1.
2.
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4.
Water
CO2
Dry-Powder
Halon
Safety Equipment
 MSDS
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Material Safety Data Sheets
The Metric System
 Decimal system of measurement
 Base of 10
 History
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France, 1791
Adopted by scientists throughout that world, 1960
International System (le Système International)
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SI
US, Liberia, and Myanmar (Burma)
 Adoption of Metric system in the US
The Metric System
 Length
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Meter
 Mass
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Kilogram
 Volume
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Liter
The Metric System - Prefixes
 micro
 milli
 centi
 deci
 deka
 hecto
 kilo
 mega
=µ
=m
=c
=d
= dk
=h
=k
=M
= one-millionth
= one-thousandth
= one-hundredth
= one-tenth
= ten times
= hundred times
= thousand times
= million times
= 10-6
= 10-3
= 10-2
= 10-1
= 101
= 102
= 103
= 106
The Metric System - Length
 1 micrometer (µm)
 1 millimeter (mm)
 1 centimeter (cm)
 1 decimeter (dm)
 1 dekameter (dkm)
 1 hectometer (hm)
 1 kilometer (km)
= 0.000001 meter
= 0.001 meter
= 0.01 meter
= 0.1 meter
= 10 meters
= 100 meters
= 1000 meters
The Metric System – Weight (Mass)
 1 microgram (µg)
 1 milligram (mg)
 1 centigram (cg)
 1 decigram (dg)
 1 dekagram (dkg)
 1 hectogram (hg)
 1 kilogram (kg)
= 0.000001 gram
= 0.001 gram
= 0.01 gram
= 0.1 gram
= 10 grams
= 100 grams
= 1000 grams
The Metric System - Volume
 1 microliter (µL)
 1 milliliter (mL)
 1 centiliter (cL)
 1 deciliter (dL)
 1 dekaliter (dkL)
 1 hectoliter (hL)
 1 kiloliter (kL)
= 0.000001 liter
= 0.001 liter
= 0.01 liter
= 0.1 liter
= 10 liters
= 100 liters
= 1000 liters
 1012 microphones = 1
megaphone
 106 bicycles = 2
megacycles
 2000 mockingbirds = 2
kilomockingbirds
 10 cards = 1 decacards
 10¯6 fish = 1 microfiche
 454 graham crackers = 1
pound cake
 1012 pins = 1 terrapin
 10 rations = 1 decoration
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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
10¯6 phones = 1 microphone
106 phones = 1 megaphone
10¯2 mental = 1 centimental
10¯1 mate = 1 decimate
10¯12 boos = 1 picoboo
The Metric System
 Temperature
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Celsius (°C)
Kelvin (K)
 Absolute zero
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0K
-273.15 °C
-459.67 F
Conversion
 Dimensional Analysis
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Factor-Label Method
Conversion
 Metric English Equivalents
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1 cm
1m
1 km
1L
1 kg
= 0.3937 in.
= 3.281 ft = 39.37 in.
= 0.6214 mile
= 0.2646 gal
= 2.204 lbs
Conversion
 K = °C + 273
 °C = 5/9(°F - 32)
 °F = 9/5(°C +32)
The Metric System
 Density
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Mass per unit volume
D = M/V
Mass in grams
Volume in cubic centimeters
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g/cm3
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Lab Procedures
 Precision
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Reproducibility
Check by repeated
measurements
Poor precision results
from poor techniques
 Accuracy
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Correctness
Check by using a
different method
Poor accuracy results
from procedural or
equipment flaws
Significant Figures
 The precision of an instrument reflects the
number of significant figures in a reading
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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 Figures
 Cardinal Rule:
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A final result should never contain any more
significant figures than the least precise data
used to calculate it.
Significant Figures
 General Rules:
1. The concept applies only to measured quantities.
2. All significant figures are counted from the first
nonzero digit.
3. All confined zeros in a number are significant.
4. Zeros that are both to the right of the decimal
point and to the right of nonzero digits are
significant.
5. The answer in an addition or subtraction problem
must be rounded off to the first column that has a
doubtful digit.
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.
Rounding
 Rules of Rounding:
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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
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
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What is it?
What is it used for?
Lab Procedures
 Recording Data/Lab Notebooks
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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
Lab Procedures
 Weighing/Balances
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Most important tool in a chemistry lab
Used to determine the mass of an object
Triple-beam balance
Analytical balance