Chemistry 1100 Keller Mizzou Exam 2

where is carbon found on our planet

reservoirs

- the atmosphere

- carbonate-containing rocks

- plants and animals (carbohydrates, proteins, lipids)

how does carbon "move"

carbon moves from reservoir to reservoir

- combustion

- photosynthesis

- sedimentation

why does where carbon ends up matter

today's carbon goes back into the atmosphere by burning fossil fuels matters because of future climate change

atomic mass

mass in grams of the same number of atoms that are found in a gram of atoms

avogadro's number

number of particles per mol substance

6.02x10^23

mol

containing avogadros number of objects

- 6.02x10^23

mole ratio

A mole ratio is ​the ratio between the amounts in moles of any two compounds involved in a chemical reaction

- can be determined by examining the coefficients in front of formulas in a balanced chemical equation

molar mass

mass of avogadro's number, or one mol, of whatever particles specified

global atmospheric lifetime

characterizes the time required for a gas added to the atmosphere to be removed aka "turnover time"

global warming potential (GWP)

a number that represents the relative contribution of a molecule of the atmospheric gas to global warming

anaerobic bacteria

bacterias that can function without the use of molecular oxygen

- many types produce methane, which then escapes into the atmosphere

sources of methane

- anaerobic bacteria

- termites

- agriculture

- landfills

- extraction of fossil fuels

sources of nitrus oxide "laughing gas"

- removal of nitrate ion (NO^3) from soils followed by the removal of oxygen

- automobile catalytic converters

- ammonia fertilizers

- biomass burning

- nitric acid and nylon production

radiative forcings

the factors (both natural and anthropogenic) that influence that the balance of Earth's incoming and outgoing radiation

albedo

the ratio of electromagnetic radiation reflected from a surface relative to the amount of radiation incident on it (measure of the reflectivity of a surface )

aerosols

a complex class of materials, that have a correspondingly complex effect on climate

- sources: dust storms, ocean spray, forest fires, volcanic eruptions, smoke, soot, sulfate aerosols from coal combustion

carbon footprint

an estimate of the amount of CO2 and other greenhouse gas emissions in a given time frame, usually a year

two things scientists need to consider when creating climate models

1) the rate of economic growth

2) the rate of development of "green" (less carbon-intensive) energy sources

weather

includes the daily high and low temperatures, the drizzles and down-pours, the blizzards and heat waves, and the fall breezes and hot summer winds, all of which have short durations

climate

regional temperatures, humidity, winds, rain, and snowfall over DECADES not DAYS

climate mitigation

is any action taken to permanently eliminate or reduce the long-term risk and hazards of climate change to human life, or the environment

carbon capture and storage (CCS)

involves separating CO2 from other combustion products and storing (sequestration) it in a variety of geological locations

climate adaptation

refers to the ability of a system to adjust to climate change (including climate variability and extremes) to moderate potential damage, to take advantage of opportunities, or to cope with the consequences

electronegativity

is a measure of the attraction of an atom for an electron in a chemical bond

- the greater the electronegativity the more an atom attracts the electrons a chemical bond toward itself

- the greater the difference in electronegativity between two bonded atoms, the more polar the bond is

polar covalent bond

a covalent bond in which the electrons are not equally shared but rather are closer to the more electronegative atom

non polar covalent bond

a covalent bond in which the electrons are shared equally or nearly equally between atoms

intermolecular force

a force that occurs between molecules

- example a H atom(+) on one of the water molecules is attracted to the O atom(-) on the neighboring molecule

hydrogen bond

is an electrostatic attraction between a H atom bonded to a highly electronegative atom (O, N, or F) and a neighboring O, N, or F atom, either in another molecule or in a different part of the same molecule

density

the mass per unit volume, of liquid water is greater than that of ice

specific heat

quantity of heat energy that must be absorbed to increase the temperature of 1 gram of a substance by 1 Celsius

potable water

water safe for drinking and cooking

surface water

the fresh water found in lakes, rivers, and streams

groundwater

fresh water found in underground reservoirs also known as aquifers

water footprints

estimates of the volume of fresh water used to produce particular goods or to provide services

solvent

a substance often a liquid capable of dissolving one or more pure substances

solute

the solid, liquid, or gas that dissolves in a solvent

solution

a homogeneous (of uniform consumption) mixture of a solvent and one or more solutes

aqueous solutions

solutions in which water is the solvent

concentration

the ratio of the amount of solute to the amount of solution is the same in each case

percent(%)

means parts per hundred

ppm

parts per million

ppb

parts per billion

volumetric flask

a type of glassware that contains a precise amount of solution when filled to the mark on its neck

non electrolyte

a solute that is nonconducting in an aqueous solution

electrolyte

a solute that conducts electricity in an aqueous solution

cation

a positively charged ion

anion

a negatively charged ion

ionic bond

the chemical bond formed when oppositely charged ions attract

ionic compound

composed of ions that are present in fixed proportions and arranged in a regular, geometric structure

polyatomic ion

two or more atoms covalently bonded together that have an overall positive or negative charge

general solubility rule

like dissolves like

surfactants

compounds that help polar and non polar compounds mix, sometimes called "wetting agents"

biomagnification

the increase in concentration of certain persistent chemicals in successively higher levels of a food chain

maximum contaminant level goal (MCLG)

the maximum level of a containment in drinking water which no known or anticipated adverse effect on human health would occur

maximum contaminant level (MCL)

the legal limit for concentration of a contaminant expressed inputs per million or parts per billion

residual chlorine

reers to chlorine containing chemicals that remain in the water after the chlorination step

trihalomethanes (THMs)

compounds such as chloroform, bromoform, bromodichloromethane, and dibromochloromethane that form from the reaction of chlorine or bromine with organic matter in drinking water

biological oxygen demand (BOD)

a measure of the amount of dissolved oxygen that microorganisms use up as they decompose organic wastes found in water

- a low BOD is one indicator of good water quality

desalination

any process that removes sodium chloride and other minerals from salt water thus producing potable water

distillation

a separation process in which a liquid solution is heated and the vapors are condensed and collected

osmosis

the passage of water through a semipermeable membrane from a solution that is less concentrated to a solution that is more concentrated

reverse osmosis

uses pressure to force the movement of water through a semipermeable membrane from a solution that is more concentrated to a solution that is less concentrated

true or false: global warming is the same everywhere

false: global warming is different everywhere

Ionian philosopher Theles

thought everything was made out of water

- required for all life

- could observe water in all 3 phases

property of water (1/3)

property: high boiling point (100C) and high freezing point (0C)

comparisons: higher than any other substance of similar molecular weight

importance: can observe all 3 phases

property of water (2/3)

property: "high" heat of vaporization (liquid to gas)

comparisons: higher than any other molecular substance

importance: condensation releases a lot of heat

property of water (3/3)

property: high heat capacity

comparisons: 2nd highest known heat capacity

importance: regulates body temperature and coastal temperatures

what makes water polar

it has a bent shape

ionic charges

atoms can give up outer electrons only

- losing an electron gives an ion a positive charge

- gaining electrons gives an ion a negative charge

molarity

the number of moles of solute (the material dissolved) per liter of solution

- used to express the concentration of a solution

why is water a good solvent (3 step process)

1. break up the solvent (partially)

- need space to insert solute particles

- have to break hydrogen bonds (costs energy)

2. break up the solute

- ions are separated

- break apart anions(-) and cations(+) (costs energy)

3. combine them together

- putting solute into solvent (gives energy back)

true or false: forming H bonds between solute and solvent releases energy

true

why don't water and oil mix

hydrocarbon (C8H18) is non-polar because its electronegativity is about the same so nothing (no partial charges) on C8H18 to attract H2O

soap (polar or non-polar)

both polar and non-polar

- the non-polar part dissolves the non-polar grease

- the polar head forms a cap around the grease glob

- the grease glob is then removed into the water

water purification: what do we need to look for and control

viruses, bacteria, metals, particulate mater, chemicals, fluorine, etc.

who controls water regulations and what are the laws they have created

EPA

- Clean Water Act (1970)

- Safe Drinking Water (1974)

how does the EPA decide what to regulate and how much to regulate

- MCLG (goal)

- MCL (legal limit)

- all in ppm or ppb

how do we make sure water is pure

find a pure source so that less treatment would be required

aquifer

an underground geological formation of porous rocks

chlorine

a little bit stays in the water after leaving the water purification plant

chloramine

still disinfects water but doesn't produce any THM's like chlorine does

ozone as a method of disinfecting

advantage: reacts quickly with microorganisms

disadvantage: costs a lot, doesn't protect the water once it leaves the plant

UV light as a method of disinfecting

advantage: high energy light, very fast, no residue

disadvantage: high cost

ultrasound as a method of disinfecting

advantage: none

disadvantage: high cost