Transcript MSC 180 – Water Analysis

MSC 180 – Water Analysis
Instructor:
Office Hours:
Jacqui Jenkins Degan
Tuesday & Thursday 1300-1500
Friday
0800-0850
Safety Equipment
Eyewash & Shower
 First Aid Kit

Fire & Fire Safety
Fire Blanket
 Fire Extinguisher

◦
◦
◦
◦
Water
CO2
Dry-Powder
Halon
Safety Equipment

MSDS
◦ Material Safety Data Sheets
The Metric System
Decimal system of measurement
 Base of 10
 History

◦ France, 1791
◦ Adopted by scientists throughout the world, 1960
◦ International System (le Système International)
 SI
Calculation Errors

Gimli Glider

Mars Climate
Orbiter

Medical Mishaps
The Metric System
BASE UNITS
 Meter
 Kilogram
 Second
 Kelvin
 Mole
 Ampere
 Candela
10n
1024
1021
1018
1015
1012
109
106
103
102
101
100
10-1
10-2
10-3
10-6
10-9
10-12
10-15
10-18
10-21
10-24
Prefix
yotazetaexapetateragigamegakilohectadeca---------decicentimillimicronanopicofemtoattozeptoyocto-
Decimal
1 000 000 000 000 000 000 000 000
1 000 000 000 000 000 000 000
1 000 000 000 000 000 000
1 000 000 000 000 000
1 000 000 000 000
1 000 000 000
1 000 000
1 000
100
10
1
0.1
0.01
0.001
0.000 001
0.000 000 001
0.000 000 000 001
0.000 000 000 000 001
0.000 000 000 000 000 001
0.000 000 000 000 000 000 001
0.000 000 000 000 000 000 000 001
Articulation
Septillion
Sextillion
Quintillion
Quadrillion
Trillion
Billion
Million
Thousand
Hundred
Ten
One
Tenth
Hundredth
Thousandth
Millionth
Billionth
Trillionth
Quadrillionth
Quintillionth
Sextillionth
Septillionth
The Metric System - Length
1 micrometer (µm)
meter
 1 millimeter (mm)
 1 centimeter (cm)
 1 decimeter (dm)
 1 dekameter (dkm)
 1 hectometer (hm)
 1 kilometer (km)

= 0.000001
= 0.001 meter
= 0.01 meter
= 0.1 meter
= 10 meters
= 100 meters
= 1000 meters
The Metric System – Weight (Mass)
1 microgram (µg)
gram
 1 milligram (mg)
 1 centigram (cg)
 1 decigram (dg)
 1 dekagram (dkg)
 1 hectogram (hg)
 1 kilogram (kg)

= 0.000001
= 0.001 gram
= 0.01 gram
= 0.1 gram
= 10 grams
= 100 grams
= 1000 grams
The Metric System

Temperature
◦ Celsius (°C)
◦ kelvin (K)

Absolute zero
◦0K
◦ -273.15 °C
◦ -459.67 F
K = °C + 273
 °C = 5/9(°F - 32)
 °F = (9/5x°C)+32

Step
Mental Arithmetic
Step
Mental Arithmetic
1. Add 40
100 + 40 = 140
1. Add 40
32 + 40 = 72
2. Multiply by 2
2 x 140 = 280
2. Multiply by 0.5
0.5 x 72 = 36
3. Subtract 10%
280 – 28 = 252
3. Add 10%
36 – 3.6 = ~40
4. Subtract 40 to
obtain final answer
252 – 40 = 212 degrees
Fahrenheit
4. Subtract 40 to
40 – 40 = degrees
obtain final answer Celsius
Conversion

Dimensional Analysis
◦ Factor-Label Method
← Conversion to English Units
English Units
Conversion to SI Units →
←Divide by
Multiply by→
SI Units
Length
Inches (in)
Feet (ft)
Yards (yd)
Miles (mi)
Square Inches (in2)
Square Feet (ft2)
Square Yard (yd2)
Square Miles (mi2)
25.4
0.305
0.914
1.61
Area
Millimeters (mm)
Meters (m)
Meters (m)
Kilometers (km)
Square Millimeters (mm2)
Square Meters (m2)
Square Meters (m2)
Square Kilometers (km2)
645.2
0.093
0.836
2.59
Volume
Fluid Ounces (fl oz)
29.57
Milliliters (mL)
Gallon (gal)
3.785
Liters (L)
3
Cubic Feet (ft )
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)
Drams (ℨ)
Grains (G)
Pounds (lb)
Short Ton (T) – 2000 lb
Short Ton (T) – 2000 lb
Fahrenheit (°F)
Celsius (°C)
Lamberts (L)
28.35
4.0
0.0667
0.4536
1016.05
907.185
Temperature
← (1.8×°C)+32
(°F-32)/1.8
°C + 273.15
Illumination
0.3183
Grams (g)
Grams (g)
Grams (g)
Kilograms (kg)
Metric Ton/Megagrams (t/Mg)
Kilograms (kg)
→
Celsius (°C)
Kelvin
Candela per Square Meter (cd/cm2)
The Metric System

Density
◦
◦
◦
◦
Mass per unit volume
D = m/V
Mass in grams
Volume in cubic centimeters
◦ g/cm3
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
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.
Significant Figures

Cardinal Rule:
◦ A final result should never contain any more
significant figures than the least precise data
used to calculate it.
Significant Figures
General Rules:
 The concept applies only to measured
quantities.

Adding & Subtracting:
◦ Decimal places are important:
500.5 + 37.222 = 537.722
Sig figs = 537.7

Multiplying & Dividing:
◦ Total significant figures are important:
15.41 x 3.2 = 49.312
Sig figs = 49
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:
◦ 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.