MSC 180 – Water Analysis Instructor:Jacqui Jenkins Degan Office Hours:Tuesday & Thursday Friday

Safety Equipment Eyewash & Shower First Aid Kit

Fire & Fire Safety Fire Blanket Fire Extinguisher ◦ Water ◦ CO 2 ◦ 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

10 n PrefixDecimalArticulation yota Septillion zeta Sextillion exa Quintillion peta Quadrillion tera Trillion 10 9 giga Billion 10 6 mega Million 10 3 kilo-1 000Thousand 10 2 hecta-100Hundred 10 1 deca-10Ten One deci-0.1Tenth centi-0.01Hundredth milli-0.001Thousandth micro Millionth nano Billionth pico Trillionth femto Quadrillionth atto Quintillionth zepto Sextillionth yocto Septillionth

The Metric System - Length 1 micrometer (µm)= meter 1 millimeter (mm)= 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

The Metric System – Weight (Mass) 1 microgram (µg)= gram 1 milligram (mg)= 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

The Metric System Temperature ◦ Celsius (°C) ◦ kelvin (K) Absolute zero ◦ 0 K ◦ °C ◦  F

StepMental Arithmetic 1. Add = Multiply by 22 x 140 = Subtract 10%280 – 28 = Subtract 40 to obtain final answer 252 – 40 = 212 degrees Fahrenheit K = °C °C = 5/9(°F - 32) °F= (9/5x°C)+32 StepMental Arithmetic 1. Add = Multiply by x 72 = Add 10%36 – 3.6 = ~40 4. Subtract 40 to obtain final answer 40 – 40 = degrees Celsius

Conversion Dimensional Analysis ◦ Factor-Label Method

← Conversion to English Units Conversion to SI Units → English Units←Divide byMultiply by→SI Units Length Inches (in)25.4Millimeters (mm) Feet (ft)0.305Meters (m) Yards (yd)0.914Meters (m) Miles (mi)1.61Kilometers (km) Area Square Inches (in 2 )645.2Square Millimeters (mm 2 ) Square Feet (ft 2 )0.093Square Meters (m 2 ) Square Yard (yd 2 )0.836Square Meters (m 2 ) Square Miles (mi 2 )2.59Square Kilometers (km 2 ) Volume Fluid Ounces (fl oz)29.57Milliliters (mL) Gallon (gal)3.785Liters (L) Cubic Feet (ft 3 )0.028Cubic Meters (m 3 ) Cubic Yard (yd 3 )0.765Cubic Meter (m 3 ) Note: All volumes greater than 1000 Liters should be in Cubic Meters (m 3 ) Mass Ounces (oz)28.35Grams (g) Drams ( ℨ) 4.0Grams (g) Grains (G)0.0667Grams (g) Pounds (lb)0.4536Kilograms (kg) Short Ton (T) – 2000 lb Metric Ton/Megagrams (t/Mg) Short Ton (T) – 2000 lb Kilograms (kg) Temperature Fahrenheit (°F)← (1.8×°C)+32(°F-32)/1.8 →Celsius (°C) °C Kelvin Illumination Lamberts (L)0.3183Candela per Square Meter (cd/cm 2 )

The Metric System Density ◦ Mass per unit volume ◦ D = m/V ◦ Mass in grams ◦ Volume in cubic centimeters ◦ g/cm 3

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: = Sig figs = Multiplying & Dividing: ◦ Total significant figures are important: x 3.2 = 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.