S2008 Chem Exam 2

Front 1

%

ratio

Back 1

% = 10^2-

ie 1% = 1 x 10^-2 = .01

Front 2

PPM

parts per million

ratio

Back 2

10^ -6

1 ppm = 1x10^-6 = .000001

Front 3

PPB

parts per billion

ratio

Back 3

10^ -9

1 ppb = 1x10^-9 = .000000001

Front 4

PPT

parts per trillion

ratio

Back 4

10^ -12

1 ppt = 1x10^-12 = .000000000001

Front 5

The polymer segment ~CH2CH2CH2CH2CH2CH2CH2~ represents

Back 5

polyethylene

Front 6

The monomer of polypropylene is

Back 6

CH2=CH-CH3

Front 7

A copolymer is composed of

Back 7

two+ different monomers

Front 8

LDPE stands for

Back 8

low density polyethylene

Front 9

LDPE finds applications as

Back 9

food wrap

Front 10

HDPE is composed of

Back 10

linear
unbranched chains
of polyethylene

closely packed

Front 11

Bottle caps are made of...

Back 11

cross-linked LDPE

Front 12

Which one of the following polymers contains aromatic functional groups?

LDPE
HDPE
polystyrene
polypropylene

Back 12

polystyrene

Front 13

addition polymers

which ones

Back 13

LDPE

HDPE

polypropylene

styrene

Front 14

grocery shopping bags made of

Back 14

HDPE

Front 15

The monomer of PVC differs from the monomer of PE by

Back 15

one atom

Front 16

monomer used to make Teflon is

Back 16

F2C=CF2

Front 17

molecule most commonly split out between monomers to make a condensation polymer

Back 17

H2O

Front 18

One example of a condensation polymer is

Back 18

nylon

Front 19

~C(=O)-CH2CH2-C(=O)-OCH2CH2O~

polymer represents a

Back 19

polyester

Front 20

original monomers

condensation v addition polymers

Back 20

Addition polymers contain all of the atoms of the original monomers, but condensation
polymers do not.

Front 21

Which of the following characteristics of synthetic polymers is NOT true?
A) They frequently give off poisonous gases when they are burned.
B) They frequently are neither biodegradable nor photodegradable.
C) They generally have a low energy content for fuel.
D) They make up a large volume of the waste which goes into landfills.

Back 21

low energy content

Front 22

why are PCBs still found in the enviro (even tho use discontinued in 70s)

Back 22

stable molecules

Front 23

Which of the following statements about phalate esters is FALSE?
A) The US currently uses phthalate esters as plasticizers.
B) Phthalate esters have been banned in the European Union as plasticizers.
C) Phalalate esters are derived from Phthalic acid.
D) The elderly are particularly suseptible to exposure to phalate esters.

Back 23

The elderly are particularly suseptible to exposure to phalate esters.

Front 24

Extra Credit: In the demo on Tuesday, the egg ...
A) floated on top of the tap water/salt water mixture.
B) sunk to the bottom of the tap water/salt water mixture.
C) floated at the interface between the tap water and salt water.
D) broke and so we couldn't do the demo.

Back 24

C- floated between tap and salt water

Front 25

% of water thats seawater

Back 25

97%

Front 26

majority of freshwater found in

Back 26

polar ice caps

Front 27

temp changes on moon between night and day no seen on earth due to

Back 27

water's high heat capacity

Front 28

fresh water must have less than __ppm dissolved solids

Back 28

500 ppm

Front 29

express 500 ppm as percent

Back 29

.05%

Front 30

1mg/L

concentration in ppm is:

Back 30

1

Front 31

Which is larger?
A) 1000 ppt B) 20 ppb C) 0.05 ppm D) 0.000001%

Back 31

0.05 ppm

Front 32

Which one of the following has the highest density?
A) water B) ice C) hexane D) octane

Back 32

WATER

Front 33

A hydrogen bond ...
A) is a bond between H on one water molecule and H on another water molecule
B) is stronger than a covalent bond
C) occurs in all three molecules: H2O, H2S and H2Se
D) none of the above

Back 33

none of above

Front 34

microscopic structure of ice is

Back 34

hexagonal

Front 35

How much heat is required to raise the temperature of 100 grams of water from room
temperature (25 °C) to boiling (100°C)?

Back 35

7,500 cal

Front 36

When a cloud composed of liquid water forms from gaseous water, heat is...

Back 36

released

Front 37

In the US, which one of the following provides the least amount of drinking water?
A) ground water B) surface water
C) desalination plants D) all are about equal

Back 37

desalination plants

Front 38

Which choice(s) below require high temperature to get drinking water?
A) osmosis B) reverse osmosis
C) distillation D) all of the above

Back 38

distillation

Front 39

what human activity causes low oxygen content

Back 39

dumping lawn clippings into lake / pond

Front 40

algae bloom stimulated in lake / pond by

Back 40

fertilizer runoff from lawn/crops

Front 41

substance likely to be produced when dissolved oxygen depleted in lake

Back 41

methane


CH4

Front 42

Under aerobic conditions, the carbon in decaying vegetation in a lake ends up primarily as

Back 42

carbon dioxide

CO2

Front 43

What plant nutrient is most responsible for eutrophication?

Back 43

PHOSPHORUS

N can also be accepted

Front 44

the Colorado river approaches the ocean, salt levels of 1000 ppm can exist in the water. This
is due to...

Back 44

irrigation

Front 45

layer of atmosphere ozone layer found in is

Back 45

stratosphere

Front 46

most abundant component of dry air

Back 46

N

Front 47

layer of atmosphere closest to earth's surface

Back 47

troposphere

Front 48

temp / pressure of
troposphere
stratosphere

Back 48

STRATOSPHERE
temp: rises further from earth's surface
pressure: falls further from earht's suface

TROPOSPHERE
temp: falls further from earth's surface
pressure: falls further from earth's surface

Front 49

atmospheric inversion occurs when

Back 49

lower layer of cool air trapped by upper layer of warm air

Front 50

Which of the following is NOT a greenhouse gas?
A) H2O B) CO2 C) Cl2 D) CO

Back 50

Cl2

Front 51

vertical mixing

troposphere v stratosphere

Back 51

more rapid in troposphere

Front 52

meridional circulation
v
zonal circulation

Back 52

meridional circulation is SLOWER

Front 53

aircraft flight over poles enter into

Back 53

stratosphere

Front 54

air rising descending

Back 54

rises in tropics descends @ poles

Front 55

word "smog" originated in

Back 55

london

Front 56

death toll in worst 5day smog episode

Back 56

>2000

Front 57

In the can demo in class on Tuesday, the can...

Back 57

imploded due to pressure reduction inside

Front 58

water solid less dense than liquid
--essential for life

Back 58

ice forms on surfaces of lakes - insulates lower layers

fish can survive winter

Front 59

ice less dense than liquid dangerous for living cells

Back 59

living tissues freeze / expand -- ice crystals rupture and kill cells

(why food manufacturers use 'flash frozen' methods -- the quicker the freeze the less the crystals expand)

Front 60

water more dense than most liquids

Back 60

liquids less dense = insoluble in water and float on top

(oil floats on water and can get wahed onto beachers)

Front 61

'heat capacity"

Back 61

quantity of heat required to raise the temp by 1*C

Front 62

specific heat

Back 62

heat capacity of a 1 gram sample

(Q of heat required to change temp of 1g by 1*C)

Front 63

water = high specific heat

Back 63

amt of heat required to change temp 1*c is a LOT

(longer and more energy)

-but stores heat well - so will stay warm or cool longer

Front 64

consequences of water's heat capacity

Back 64

water on earth acts as heat reservoir that moderates daily temp variations

**why teh moon (waterless) has EXTREME temp variations from day - night**

Front 65

heat of vaporization

Back 65

large amt of heat required to evaporate small amt of water

Front 66

water high heat of vaporization
consequences

Back 66

important bc large amt of body heat can be dissipated by evaporation of small amts of water(sweat) from skin

also accounts for climate-modifying properties of lakes / oceans
--- large portion of heat that would normally heat land - vaporizes water from surface of lakes / seas (ie weather is cooler near bodies of water)

Front 67

water's liquid state

Back 67

molecules tumbling over another
but associated thru strong H-bonds

tumbling = more and more violent until boiling pt reached
(some molecules have enough energy to break all of the H-bonds with molecules around them and fly into gas phase)

Front 68

water freezing

Back 68

molecules take on more ordered arrangement

forming 4 H-bonds per molecule

contains large hexagonal holes
(holes collapse when ice melts)

3d structure

Front 69

water's polarity and salty seawater

Back 69

readily dissolves most IONIC substances

(accounts for saltyness of sea)

rainwater dissolves ions of minerals -- these ions carried by streams etc to sea
.... heat of sun evaporates part of water -- leaving salt behind

Front 70

most of rain

Back 70

falls into sea or other innaccessable areas

Front 71

polar ice caps %

Back 71

2% of total water

Front 72

available freshwater

Back 72

<1%

most underground

(lakes and streams = .01% of freshwater)

Front 73

"potable" water

Back 73

suitable for drinking

Front 74

deaths / year due to contaminated water

Back 74

3.6 million

Front 75

rainwater not pure H2O

Back 75

carries dust particles & dissolves oxygen, N, & CO2 as falls thru air

Front 76

natural rainwater slightly acidic

Back 76

due to absorbing CO2

CO2+ H2O --> H2CO3

Front 77

lightning & rain

Back 77

N, O2, & water vapor combine into
NITRIC ACID

(which dissolves in rainwater as well)

Front 78

groundwater contains radon

Back 78

naturally occuring gas

product of decay of radioactive uranium and thorium

emits damaging ionizing radiation

ONLY SLIGHTLY SOLUbLE IN WATER
(thus water used doesn't contribute very much to total radon in indoor air)

Front 79

dissolved minerals

Back 79

as water moves along or beneath surface dissolves minerals from rocks / soil

minerals (SALTS) = ionic (either + or - charged)

Front 80

principle cations in natural water

Back 80

Na+

K+

Ca2+

Mg2+

Fe2+ or Fe3+

Front 81

principle anions in natural water

Back 81

(SO4)2- ... sulfate

(HCO3)- ... bicarbonate

(Cl)- .... chloride

Front 82

"hard water'

Back 82

water containing Ca, Mg, or IRON SALTS

positive ions react w negative ions in soap to form scum

Front 83

soft water

Back 83

may contain ions (Na+ or K+) but don't form insoluble scum with the soap

Front 84

water cycle

Back 84

replenishes supply of fresh water

water evaporates from sea -- salts left behind

-moves thru ground - impurities trapped in rock / gravel

Front 85

waterborne disease

Back 85

pathogenic microorganisms from human waste

started in 1830s
cholera epidemics
typhoid fever
dysentary

due to today's chemical treatment of water - safe
(disease still commmon in asia africa latin america)

ongoing threat - cryptosporidium (resists standard chemical treatment)

Front 86

acid rain

Back 86

acids formed form sulfur oxides (SOx) & nitrogen oxides (NOx) corrode metal / dissolve limestone/marble
*mainly from coal-fired power plants*

acids can also flow into streams from abandoned mines

Front 87

acid rain affecting living organisms

Back 87

-cause release of toxic ions from rock /soil
(AL3+ ions tightly bond to clays are released by acid - deadly to fish)

Front 88

prob with human sewage in water

Back 88

breakdown of organic matter by bacteria depletes dissolved O2 & enriches water with plant nutrients

organic material can be degraded by microorganisms
-biodegration can be aerobic or anearobic...

Front 89

aerobic oxidation

Back 89

occurs in presence of dissolved O2

(BOD-biochemical oxygen demand= measure of O2 needed for degradation)

-the more organic waste, the higher the BOD

-if BOD is high enough dissolved O2 depleted and no life (other than anaerobic microorg's) can survive

*flowing streams can regenerate as flowing water dissolves oxygen (lakes with no flow can remain dead for years)

*with adequate dissolved O2 aerobic bacteria oxidize organic matter to CO2, H2O, and inorganic ions

Front 90

eutrophication

Back 90

with adequate dissolved O2 aerobic bacteria oxidize organic matter to CO2, H2O, and inorganic ions

ions (esp nitrates / phosphates) serve as nutrients for algae

when algae die become organic waste & increase BOD ("EUTROPHICATION")

eutrophication - natural process but accelerated by human waste, phosphate from detergents, and fertilizer runoff

Front 91

anaerobic decay

Back 91

too much organic matter depletes teh dissolved oxygen -- anaerobic decay takes over

(instead of oxidizing organic matter - its reduced)---
methane (CH4) is formed
-sulfur converted to hydrogen sulfide (H2S) (badsmelling)
-N reduced to ammonia

foul odors = indicate water overloaded with organic waste

Front 92

fertilizer runoff

Back 92

add inorganic nutrients to the cycle

-- algal bloom can lead to oxygen depletion -- death to fish

Front 93

ppl get their water from

Back 93

1/2 surface water
1/2 groundwater

rural areas 97% groundwater

Front 94

aquifer

Back 94

forms when water bearing rocks readily transmit water to wells / springs
-wells drilled into aquifer

precipitation recharges aquifer

most pumping rate > recharge rate = water table drops
(wells must be drilled deeper and deeper)

Front 95

well water can be contaminated

toxic chemicals found in groundwater in some areas

Back 95

*once conatminated, an aquifer may remain unusable for decades+


- MTBE (methyl tertbutyl) gasoline additive -- undrinkable

-waste from production of pesticides (rocky mountain area)

-creosote -- chemical used as wood preservative 9near minneapolis)

-aldicarb - pesticide for potato crops (long island & WI)

- contamination with industrial waste(NJ)

Front 96

nitrates

groundwater contamination

Back 96

agricultural areas
water contaminated with nitrate ions (NO3-)

esp dangerous to infants (digestive trat nitrate reduced to nitrite)= blue baby syndrome

come from fertilizers / decomposition of organic wastes in sewage treatment / runoff from animal feed lots

*highly soluble === difficult to remove*

Front 97

volatile organic cemicals
VOCs

groundwater contamination

Back 97

add odor to water

many are suspected carcinogens

VOCs used as solvents / cleaners / fuels -- components of gasoline

common: hydrocarbon solvents (benzene chlorinated hydrocarbons)

Front 98

leaking underground storage tanks (USTs)

groundwater contamination

Back 98

contain petroleum or hazardous chemicals

buried steel tanks

last ~15yrs before rust thru and leak

(1980s = 2.5 million USTs)

Front 99

Safe Drinking Water Act

Back 99

1974

gives EPA power to set / moniter / enforce health standards

Front 100

1 ppm solute in solution ....

Back 100

same as
1 g solute per 1 million g solution

(1g solute/10^6 g solution)

and
1 PPB = 1g solute / 10^9g solution

Front 101

water treatment -1st

Back 101

water placed in settling basin -- treated with slaked lime and a flocculent (such as alum)
--these materials react to form gelatinous mass of aluminum hydroxide

aluminum hydroxide carries down dirt particles and bacteria

water then filtered thru sand and gravel

Front 102

water treatment - chemical disinfection

Back 102

final step

chlorine added to kill remaining bacteria

(question use of chlorine bc converts dissolved organic compounds into chlorinated hydrocarbons)

EUROPE - uses ozone to disinfect drinking water
--more expensive
--but less needed
**ozone transfers its extra oxygen to the contaminent -- oxidized contaminants less toxic than chlorinated onesn