Reminder Register Iclicker Quiz 1 on Tuesday Jan 27 Sign up for a group by Saturday I will send instruction today Starting from Tuesday you will sit with your group Check syllabus and schedule on compass 1 Environmental Measurements CEE 330 2 1 2 4 Textbook I am familiar with A Calculating chemical concentrations and converting chemical concentration to parts per million ppm or parts per billion ppb basis B Calculating chemical concentration in unit of partial pressure C Using the ideal gas law to calculate gas concentration D All of the above E None of the above 3 1 micro gram g is equal to A B C D E 10 12 g 10 9 g 10 6 g 10 3 g None of the above 4 Select the correct statement A Parts per million by mass ppm is defined as the number of units of mass of chemical per million units of total mass B 1 ppm of chemical i means 1 g of i in 106 g total C 1 ppb of chemical i means 1 g of i in 106 g total D A and B E B and C 5 Conversion mi 6 10 ppm mtotal mi 9 10 ppb mtotal 6 Concentration in Soil If a 100 g sample of soil contains 10 5 g of toxaphene what are the toxaphene soil concentrations reported in units of ppb A B C D E 1ppb 10 ppb 100 ppb 1000 ppb None of the above 7 10 5 g toxaphene 9 10 100 ppb 100 g soil 8 Concentration in water A water sample contains 10 mg NO3 L What is the concentration in ppm A B C D E 1 ppm 10 ppm 100 ppm 1000 ppm None of the above 9 6 10 mgNO L water 10 mg 10 10 kg 3 Concentration of NO3 1 kg water L water 1kg 1kg 1 kg of water 1 L of water Conversion to ppm 10 10 6 kg 106 10 ppm as NO3 1kg 10 Concentration in water A water sample contains 10 mg NO3 L What is the concentration in moles L MW NO3 62 g mole A B C D E 1 6 10 1 moles L 1 6 10 2 moles L 1 6 10 3 moles L 1 6 10 4 moles L None of the above 11 Molecular weight MW of NO3 62 g mole 10 mg 1g 1 mole Concentration of NO3 L 1 000 mg 62 g 4 1 6 10 moles NO3 L 12 Concentration in water A water sample contains 10 mg NO3 L What is the concentration in mg NO3 as N L MW NO3 62 g moles and MW of N 14 g mole A B C D E 1 6 10 1 moles L 1 6 10 2 moles L 1 6 10 3 moles L 1 6 10 4 moles L None of the above 13 10 mg NO3 1 mole NO3 1 mole N 14 g N L 62 g NO3 1 mole NO3 1 mole N 2 3 mg NO3 N L 14 Carbon Dioxide And Global Warming How Do We Know 15 Composition of the clean atmosphere GAS MIXING RATIO mol mol 1 Nitrogen N2 Oxygen O2 Argon Ar Carbon dioxide CO2 0 78 0 21 0 0093 380x10 6 Neon Ne Ozone O3 18x10 6 0 01 10 x10 6 Helium He Methane CH4 5 2x10 6 1 7x10 6 Krypton Kr 1 1x10 6 16 Mixing ratio or mole fraction CX mol mol 1 moles of X CX moles of air X represents any compound e g O2 17 Mass concentration g cm 3 mass of X X unit volume of air X and CX are related by the ideal gas law 18 Monitoring trace gas The upper safety limit for atmospheric CO2 is 350 parts per million ppm Atmospheric CO2 levels have stayed higher than 350 ppm since early 1988 19 Concentration in Air can be expressed as Partial pressure atm ppmv and ppbv Mass per volume g L or mole L Trace gas concentration units 1 ppmv 1 mol mol 1 1x10 6 mol mol 1 1 ppbv 1 nmol mol 1 1x10 9 mol mol 1 1 pptv 1 pmol mol 1 1x10 12 mol mol 1 20 How does concentration relate to pressure and temperature A PV RT B PV nRT C Not sure P pressure V volume T temperature in K 0 C 273 K n number of moles concentration n V R gas constant 21 Concentration in Air g Vi 1 6 1 ppmv 10 3 Vtotal m MWi RT 6 10 P g Vi 1 9 1 ppbv 10 3 Vtotal m MWi RT 9 10 P 22 Example Convert 260 g m3 SO2 at 28 C and 1 atm to ppmv and ppbv g RT 1 6 10 ppmv 3 m P MW m3 atm 260 g 10 6 g 8 205 10 mole K 301K 1 6 10 0 100 ppmv 3 g 1atm 64 g mole m 5 0 100 ppmv 103 ppbv 100 ppbv ppmv 23 The concentration of gas phase PCB in the air above Lake Superior was measured to be 450 pg m3 What is the partial pressure in atm of PCBs Assume that temperature is 0 C the atmosphere pressure is 1 atm and the average MW of PCB is 325 Also assume that 1 mole of air at 0 C and 1 atm occupies 22 4 L 24 Ideal Gas Law Relates Concentration to Pressure PV nRT nRT P V P pressure V volume T temperature K n moles R gass constant value depends on units of P and V 25 Steps for solving pg g Convert 3 to m air L air g mole Convert to L air L air mole Convert to partial pressure L air 26 The concentration of gas phase PCB in the air above Lake Superior was measured to be 450 pg m3 What is the partial pressure in atm of PCBs Assume that temperature is 0 C the atmosphere pressure is 1 atm and the average MW of PCB is 325 Also assume that 1 mole of air at 0 C and 1 atm occupies 22 4 L 27 pg g Convert 3 to m air L air 3 pg g m g 12 3 15 450 3 10 10 450 10 m air pg L L air g mole Convert to L air L air mole 15 g 15 mole 450 10 1 38 10 L 325 g L air mole Convert to partial pressure L air nPCB RT nPCB 15 mole 1 38 10 PPCB L 3 1 10 14 V V nair RT nair 1 mole Pair 22 4 L V V PPCB 3 1 10 14 Pair 3 1 10 14 atm 28 Concentration in air The concentration of ozone O3 in Beijing on a summer day T 30 C P 1 atm is 125 ppbv What is the O3 concentration in units of g m3 MW of O3 48g mole 29 Vi 1 ppbv 109 Vtotal Assume Vair 109 m3 …
View Full Document
Unlocking...