CHEM 104 Final Exam (Hill)
How much of earth is salt water?
97%
Non-Electrolyte
A substance that dissolved in water to give a solution that does not conduct an electric current
Electrolyte
A substance that is dissolved in solution and some of its molecules split or dissociate into electrically charged atoms or ions
What factor is considered in determining the global warming potential for a particular molecule?
Ability to absorb and re-emit IR radiation
What's the largest size estimate for the Ozone hold over the Antarctic?
About as large as North America
Ozone depletion is a ____ problem
Global
Heterogenous Mixture
Mixture with uneven distribution of different substances; not the same throughout
What does increased intensity of UV radiation yield?
More Ozone production
Pneumonic for Hydrocarbon prefixed
Mother Eats Peanut Butter Methane, Ethane, Propane, Cyclopropane
Ozone Molecule
O3
Which statement is false? O2 is an element Carbon monoxide is a diatomic molecule Air is a Mixture H2O is a compound
Carbone dioxide is a diatomic molecule
Low to moderate risk according to UV index
1-5
Unique Properties of Water (4)
1. Liquid at room temperature 2.High boiling point 3.Expands when frozen 4.Specific heat/absorbs heat well
1ppm =
1mg/L
H2O molecule positive part
2 Hydrogens
Compounds
2 or more elements chemically combined; Completely the same chemical combination throughout
How many tons of ozone is made and used daily?
300,000,000 tons
A Calorie is defined as...
4.184 J Therefore 1 cal = 1000 Cal
High risk value according to UV index
6-11+
How much of the earth is water?
71%
Composition of Air
78% Nitrogen, 21% Oxygen, 1% Argon and CO2
Which color in the rainbow has the shortest wavelength?
Blue
In forming a solution the solute ___ other substances that are called solvents
Dissolves
Wavelength
Distance between successful peaks; Expressed in nanometers (nm)
Which type of water may be considered pure?
Distilled Water
Ozone in our atmosphere is important because it ... A. absorbs some IR radiation. B. destroys trees. C. reacts with excess CO2. D. reflects IR radiation. E. No answer because all the options above are not correct
E. None are correct
Ionic Bond
Gaining/Losing an electron to another atom
A gasolines octane rating is a measure of the...
Gasoline's resistance to causing knocking in a vehicle's engine
Valence Electrons
The electrons in the outermost shell of an atom; these are the electrons involved in forming bonds
What is Kinetic Energy?
The energy of motion
What is Potential Energy?
The energy stored in the chemical bonds (Fossil fuels=example)
Radiant Energy
The entire collection of different wavelengths, each with own energy
What is Entropy
The measure of how much energy is dispersed in a given process Relates to the 2nd Law of Thermodynamics
Ozone depletion Involves ___ radiation
UV
Which region of the Ultraviolet spectrum is absorbed least by the atmosphere?
UV-A
Types of UV Light
UV-A (Least energetic) (320-400nm) (Reaches Earth most often) UV-B (280-320nm) (partially absorbed by Oxygen) UV-C (Most energetic) (200-280nm) (Absorbed by oxygen and ozone in atmosphere)
What UV light causes skin cancer?
UV-B and some UV-A
Noble Gases Properties
Un-reactive nonmetals
Least Hazardous source of Fresh Water?
Underground Aquifers
What is a Mole?
Unit used to find the weight of atoms
How are CFC's made?
Unnaturally created for old fridges, aerosol sprays, housing insulations
Surfactant
Used to dissolve polar and non-polar bonds at same time because contains both
Is NACL an electrolyte?
Yes, ionic bonds always conduct electricity
Mixture
a physical combination of two or more substances present in variable amounts
Water Footprint
a rough measure of the volume of fresh water that we use to keep a person or group alive and to support their lifestyles
Stratospheric ozone is destroyed and formed at the same rate...
above the equator and above the Antarctic in its early fall
You wear sunscreen on your skin in order for the sunscreen to ___
absorb UV-A and UV-B radiation
Ozone in the stratosphere is important because it...
absorbs some UV radiation
Most fresh water is used for ___
agriculture
How do we use molarity to measure solution?
find molar mass of compound, put over 1 liter=1 Molarity=Moles of solute/Liters in Solution
The Montreal Protocol is a...
Treaty to reduce the amount of CFCs produced in the world
Climate change takes place in the ...
Troposphere
If we assume that the top of Mt. Everest is the highest land mass on earth, hikers who scale its summit are standing in the...
Troposphere
Which is the lower region of the atmosphere in which we live?
Troposphere
A polar covalent bond is created when...
Two atoms share their bonding electrons unequally
Covalent Bonds are only formed by ___ + ___
Two nonmetals
What is a Solvent?
It dissolves solutes
Why isn't sugar an electrolyte?
It has covalent compounds
What is the effect of infrared energy on matter?
It increases the vibration of chemical bonds
What is the Second Law of Thermodynamics?
It is impossible to completely convert heat into work without making other changes in the universe 'There is no perfect machine' Entropy is related to that
Why is H2O so reactive?
It's polar and has 2 unshared electrons
Which element is not a halogen? F I Kr Br
Kr
Air Quality Index
Scale that ranks levels of ozone and other air pollutants (0-500) 500=high
Climate change causes ___
Sea level and global temperature rising
Electromagnetic Spectrum
The arrangement of waves of radiant energy in order of wavelength and frequency
Cracking is...
The breaking of larger molecules into smaller ones Major catalyst in the Petroleum refining process
Ionic Bonds are between non-metal and...
Metal
How to measure conductivity of solution?
Conductivity meter
Air Quality index for Healthy-Moderate Air
0-100
Amount of AVAILABLE fresh water
0.1%
H2O molecule negative part
1 Oxygen
O2 and O3 molecules are...
Allotropes
Properties of the Infrared Region on the Electromagnetic Spectrum
Feel heat, invisible
How to find Molar Mass?
Find number below large letter on Periodic Table and convert into grams
What is a proper use for a calorimeter?
For measuring the heat of combustion
Intermolecular Force
Forces of attraction between 2 MOLECULES
____ are highly reactive chemical species with one or more unpaired electrons
Free Radicals
What causes the destruction of Ozone?
Free radicals of Hydrogen, Hydroxyl, Nitrogen, CFC's and Halons
Groundwater
Fresh water found in underground reservoirs also known as aquifers
Air is a... element compound mixture pure substance
Mixture
Is air a mixture or a pure substance?
Mixture
Homogenous Mixture
Mixture in which the composition is uniform throughout
PPH to PPM conversion
Move decimal four places to the right
The Carbon Cycle refers to the...
Movement of carbon through living organisms, the atmosphere, the sea, and the earth
Mole Conversion to grams
Multiple given moles by the molar mass in grams over one mole
Gram conversion to Mole
Multiply gram amount by 1 mole over total atomic weight (atomic mass in grams)
The heat energy released or absorbed by a chemical reaction is generally determined by the difference between the energy that...?
Must be put into to break the bonds in the reactants and the energy that is released upon making the bonds in the products
Is sugar an Electrolyte?
NO
Was the Kyoto Protocol ratified by the US?
NO
Anion
Negatively charged ion
Electrons
Negatively charged particles outside nucleus
Neutrons
Neutrally charged particles inside nucleus
Combustion is a chemical process in which a fuel combines with ____ to release energy and form products
Nitrogen
List the three most abundant components in the atmosphere in decreasing order...
Nitrogen > Oxygen > Argon
Air Particles unchanged by respiration?
Nitrogen and Argon
Covalent bonds are between non-metal and...
Non-Metal
Hetero compounds (H2) will always be...
Non-polar, Linear
What does the Atomic number tell you?
Number of protons in the nucleus. Always equal to the number of electrons (if stable)
List the 4 steps of the Chapman Cycle
O2 -> 2 O O+O2->O3 O3->O+O2 (Involves radiation) O+O3->2 O2
Which component of the air is an Element? H20 NO2 O3 CO2
O3
Ionic Bonds are only formed by ___+___
One non-metal and one metal
Ozone depletion if happening in the...
Stratosphere
Where is the ozone layer found?
Stratosphere
How to get number of neutrons using the Periodic Table?
Subtract atomic number from the mass number
Mass Number
Sum of the number of neutrons and protons in an atomic nucleus; tells you the isotopes
Which country has the highest per capita emission of carbon dioxide?
The United States
Bromide II has charge of...
2+
Intramolecular Force
A force that exists within a molecule
What happens in an Endothermic process?
Any chemical or physical change that absorbs energy
What is a Solute?
What is being dissolved in a Solvent
What would be the temperature on earth in the absence of the effects of carbon dioxide and water?
-18 Degrees C
Types of light waves on the Electromagnetic Spectrum (From smallest to largest)
(From smallest to largest) Gamma, x-ray, UV, Visible, IR, Microwave, Radio (Smallest=Higher frequency, shortest wavelengths)
Polyatomic Ions
A covalently bonded group of atoms that has overall positive or negative charge
Molecule
A group of atoms bonded together
What is Electronegativity?
A measure of an atom's attraction for an electron in a chemical bond
What is electronegativity?
A measure of the ability of an atom in a chemical compound to attract electrons
Elements
A molecule composed of one kind of atom; cannot be broken into simpler units by chemical reactions
In which example is the entropy of the initial state lower than the entropy of the final state? (Ice, Water, Vapor)
A pot of water boils to produce water vapor at 100 Degrees Celsius
Distillation
A process that separates the substances in a solution based on their boiling points, used to clean salt water
What is not a possible consequence of global warming?
An increase in pH (basicity) of the surface ocean water
What is groundwater?
Any water taken from aquifers
What is the relationship between stratospheric levels of atomic chlorine and ozone?
As chlorine increases, ozone decreases
What is Molar Mass?
Atomic Mass in Grams
AMU
Atomic Mass per Unit; get from Mass Number on Periodic Table
Isotope
Atoms of the same element that have different numbers of neutrons
How did the world respond to CFC's?
Banned them in spray cans and phased out of products
How to find Atomic Mass?
Below the letter on the Period Table
What is the best way to combat climate change?
Burn less coal; lessens the amount of pollution in the air
How does the destruction of the ozone happen?
By an interaction of CFCs with chlorine free radicals
Scientists have correlated average global Temperature with atmospheric CO2 using Ice cores from Antartica. How is the carbon dioxide level determined?
By measuring the CO2 concentration in trapped gases in the ice layers (Bubbles)
HFC's may be used to replace CFC's. Which compound is a HFC?
CF3CH2F
Which has the greatest GWP (Global warming potential) value?
CFC-12-CCl2F2
Climate change involves ___ radiation
CO2
Which component of the air makes up approx. 100 times more of an exhaled breath than of an inhaled breath?
CO2
Which one is not an air pollutant? CO NO2 SO2 CO2
CO2
Which substances are regulated by the Kyoto Protocol?
Carbon Dioxide, Nitrous Oxide, Sulfur Hexafluoride
Name 5 kinds of Air Pollutants
Carbon Monoxide, Ozone, Sulfur Dioxide, Nitrogen Dioxide, Particulate Matter (dust, sand)
Which statement is false about Catalytic Converters?
Catalytic Converters in automobile tail pipes utilize nitrogen gas to burn VOCs to form CO2 and H2O
Free Radicals
Chemical particles with an off number of electrons; bond very quickly and do many reactions
Which product of the ultraviolet decomposition of CFCs acts as the catalyst for ozone decomposition?
Chlorine Atoms
What chemical directly catalyzes the destruction of ozone?
Chlorine free radicals
Which is the major contribution to the ozone hole?
Chlorofluorocarbons (CFCs)
What are CFC's?
Chlorofluorocarbons (chemicals) that break down the ozone layer
How do CFC's hurt the Ozone?
Cl-C bond broken by UV-C; Becomes CL free radical; Steals 1 O from O3; it quickly loses this O to another lose O to kill more ozone
Which explanation accounts for the fact that, on average, cloudy nights are warmer than clear nights?
Clouds are composed of water vapor and H2O is a strong greenhouse gas
Can recognize ionic bonds due to...
Combination of left and right of staircase on Periodic Table
Salt, Sugar, and Ethanol are all ___ solutes
Completely dissolved
Solutes can be dissolved by H2O ___ or ___
Completely or partially
Halons
Compounds similar to CFC's, in which bromine or fluorine atoms replace some or all of the chlorine atoms; more dangerous
Isomers are...
Compounds with the same chemical formulas, but different molecular structure
List the order of rays from highest energy to lowest energy:
Cosmic Rays, Gamma Rays, x-ras, Ultraviolet rays, visible light, infra-red, microwaves, radiowaves
During Petroleum refining, catalysts play an extremely important role during the...
Cracking and Reforming Process Process of breaking higher hydrocarbons into lower ones and converting open chain hydrocarbons
Density Equation
D = 1g/cm3
What is the single most effective strategy to reduce carbon dioxide emissions?
Develop alternate energy sources that do not rely on fossil fuels
What is the objection to the Kyoto Protocol?
Developing countries are not required to control greenhouse gas emissions
Future of Ozone layer
Disappearing by 2/3 holes constantly over poles
A molecule with only polar atoms can be ___
Either polar or non-polar
Who is most at risk for skin cancer?
Elderly; due to overexposure over the years
What causes water's uniqueness?
Electronegativity and water molecule's polarity
Classification of pure substances
Elements and Compounds
The First Law of Thermodynamics states that...
Energy is neither created nor destroyed "Conversion of Energy
What is the Activation Energy?
Energy needed to intimate a chemical reaction
What is Heat?
Energy that flows from a warmer body to a colder body
What is the relation of Entropy to the 2nd Law of Thermodynamics?
Entropy of the Universe is constantly increasing
What can decrease the activation energy of a reaction?
Enzymes and Catalysts can decrease the activation energy
Where is UV intensity highest?
Equator
True or False: Carbon Dioxide is a greenhouse gas but methane (CH4) is not
False
Water availability is influenced by... (3)
Global climate change, overconsumption, contamination
Results of the Montreal Protocol include...
Greatly reduced production of CFCs Increased production of alternatives to CFCs Recycling of CFCs
What does an element's group tell us?
Group is the vertical column. Tells us how many valence electrons are in the outer shell; tells us how reactive the element is
Which covalent bond is the most polar?
H - O
The ____ concentration in the air over the desert differs dramatically from that in the air in the tropical rain forest
H2O
How does Water vapor hurt the Ozone Layer?
H2O evaporates and reaches the ozone layer. UV light breaks H2O, making Hydrogen and Hydroxyl Free Radicals. These steal 1 O from O3, making O2
Why are HFC's Environmentally superior to the currently used HCFCs?
HCFCs contain chlorine while HFCs do not contain chlorine
What happens in an Exothermic chemical reaction?
Heat is released as the reaction proceeds
Types of Mixtures
Heterogenous and Homogenous
Fast/Shorter waves means...
Higher frequency
Alkali Metals Properties
Highly reactive metals
Steady State
Homeostasis in Ozone layer in terms of O2 and O3
What is a Solution?
Homogenous mixture of dissolved solute and solvent
What do periods mean on the Periodic Table?
How many valence shells there are
Frequency
How many wave peaks pass a certain point per given time
What is UV light harmful to?
Humans, small marine life, Bacteria and viruses
One replacement for CFC's are ____ which are compounds of hydrogen, carbon, fluorine, and chlorine
Hydrochlorofluorocarbons
How to measure if compound is polar or non-polar?
If given electronegativity of elements, compare to see if balanced. If not and difference is greater than 2.0, it's POLAR
Where is most of the carbon on Earth stored?
In the form of fossil fuels and carbonate minerals and rocks
Electronegativity on Periodic Table
Increases left to right, decreases by moving down column; Oxygen and Fluorine are highest; LAST COLUMN IS NOT ELECTRONEGATIVE
Water has one of the highest specific heats of any known liquid. This means that the temperature of a water sample ___ with the input of a ___ amount of energy
Increases only slightly; Large
Which approach would help most to reduce indoor air pollution?
Increasing the air exchange
CO2 Absorbs energy in the ___ part of the EM spectrum
Infra-Red
Chlorofluorocarbons rise to the Stratosphere and...
Interact with UV energy to produce free radicals that destroy ozone
Which is stronger? Covalent or Ionic Bonds?
Ionic
Potable water is water that...
Is safe to drink and to cook with
How does UV damage cells and what can that do?
Light energy (photons) goes into cells and causes mutations with skin cells. Can cause skin cancer, retinal damage, and cataracts
What happens when UV hits the skin?
Light energy (photons) goes into cells; if there's enough energy, they will come apart from the inside; can cause cell death and suntan
In which transition is the entropy of the initial state greater than the entropy of the final state? (Ice, Water, Vapor)
Liquid water freezes into ice
Long/Spread out waves means...
Low Frequency
Atomic Mass definition
Mass in grams of the same number of atoms
AMU Definition
Mass of 1/12 of Carbon-12
How does climate change affect water availability?
Melting glaciers, takes water from people who use them, floods/droughts
Inventor of Periodic Table
Mendeleev
Polar Compound Effect
Only part of it attracts electrons, so the positive/negative balance is off
Hydrocarbons
Organic molecules consisting of only carbon and hydrogen. Have different prefixes than other molecules used for fuels
Air Particles changed by respiration?
Oxygen and CO2
Which air pollutant would be most likely to depend on air temperature for its production?
Ozone
Types of solution concentrations (4)
Percents, PPM, PPB, Molarity
H2O is polar or non-polar?
Polar
How do bonds effect solutions dissolving solutes?
Polar bonds dissolve polar bonds, "Like with Like"
What is a Cation?
Positively charged ion
Protons
Positively charged particles inside nucleus
Types of water (2)
Potable and non-potable
To be electronically stable, an atom must have an equal number of ___ and ___
Protons and Neutrons
Combustion
Rapid reaction between oxygen and fuel that results in heat and light
UV Index
Rates the amount of damaging UV radiation is entering the Earth's atmosphere and reaching the surface
Halogens Properties
Reactive non-metals
Goal of the Montreal Protocol in 1987 included...
Reduce the amount of new production of CFC's in developed countries; recycle existing CFC's rather than release them into the air; encourage research into substitutes for CFC's
Possible consequences of Global Warming (4)
Rise in sea level; increase in average relative humidity; increase in forest growth in northern hemisphere; weakening of ocean currents
Chapman Cycle
Series of chemical reactions responsible for the formation and destruction of ozone in the stratosphere. Occurs when UV-C light is absorbed by O2. The 02 breaks into 2 O, which each bond to a different O2 molecule, making O3
The fact that a carbon (C) is less electronegative than nitrogen (N) means that in a C-N bond, the...
Shared electrons are closer to the N atom then to the C atom
Ozone depletion causes ___
Skin cancer in high contact
Atom
Smallest particle of an element
Ozone Pollutant
Smelly gas that can cause breathing problems
Aqueous Solutions
Solutions in which water is the solvent
How to prevent skin cancer:
Sunscreen that absorbs UV A and B
Types of Potable water (3)
Surface water, ground water, atmosphere
What is Temperature?
Tells about the direction of heat flow
What happens when 2 H2O's are close-by?
The H is attracted to the O on the other because + likes the -
Surface Water
The fresh water found in lakes, rivers, and streams
How is polarity affected by electronegativity?
The greater difference in electronegativity between 2 bonded atoms, the more polar it will be
Greenhouse Effect
The process in which atmospheric gases trap and return more than 80% of the heat energy radiated by the Earth
Which common process on earth is endothermic?
The production of oxygen by photosynthesis
What is Specific Heat?
The quantity of heat energy that must be absorbed to increase the temperature of one gram of a substance one degree Celsius
Which is not true about free radicals?
They are very stable chemical species
What types of light energy can we see?
Visible light (400-700nm)
How do we measure concentrations in lab?
Volumetric Flask
Frequency is inversely related to...___
Wavelength
Hydrogen Bonds
When hydrogen is attracted to and bonds with a very electronegative atom (O,N,F) and a nearby atom with high electronegativity (O,N,F); can be on different atoms or same one
Things that affect chances of getting skin cancer:
Where you live (equator=more risk), when you go outside (10am-4pm=most UV rays), clothing, tanning, following media warnings, genetics
As the ozone hold gets more pronounced, with time, one expects the incidence of skin cancer to...
increase worldwide
Speed of light in air...
is independent of the wavelength and frequency of light
A molecule with only non-polar bonds will always be ___
non-polar
During the Antarctic Spring, ozone is destroyed at a greater rate than it is formed...
on the surface of the atmospheric ice crystals; in a process that is catalytic; in polar stratospheric clouds
Covalent Bond
sharing a pair of electrons between atoms
Concentration
the amount of solute to solution (ex: Sugar to water)
Hydrogen Bonding
the intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule
What is a Calorimeter?
the process of measuring the heat of chemical reactions or physical changes as well as heat capacity
When assessing the risk of an air pollutant, which does not play a role in considering someone's exposure to the pollutant?
the toxicity of the pollutant
