Chemistry Final

Question Answer
H-bonds are? intermolecular bonds.
Covalent bonds are? intramolecular bonds.
Intermolecular bonds are? weak.
Intramolecular bonds are? strong.
Hydrogen bonding is? weak forces.
Ice expands and is less dense than? water. Reason ice floats is because it expands and is less dense when it forms as a solid.
A solution is a homogenous mixture of? uniform composition. Solutions are made up of solvents and solutes.
Solvents are? substances capable of dissolving other substances usually present in the greater amount.
Solutes are substances dissolved? in a solvent usually present in the lesser amount.
When water is the solvent, you have an? aqueous solution.
70% of the earth's surface is? water. 97% of our water is oceans. 3% is freshwater.
Water molecule is a? bent shape.
electronegativity is a measure of an atom's? attraction for the electrons it shares in a covalent bond.
Polarity is the difference between?
A difference in the electronegatives of the atoms in a bond? creates a polar bond.
A polar covalent bond is a covalent bond? in which the electrons are not equally shared, but rather displaced toward the more electronegative atom.
A water molecule is polar due to? polar covalent bonds and the shape of the molecule.
Polar solids will dissolve polar? substances, non-polar solids will dissolve non-polar substances.
Parts per million? A concentration of one part out of a million. One ppm is a unit of concentration 10,000 times smaller than 1% ( one part per hundred). 1.2 and 5.5.
Molarity is the number of moles of? a solute per a liter solution.
To calculate molarity you divide the number of moles by? liters. moles/ liters.
Sugar dissolved in water? non- conducting is a nonelectrolyte.
NaCl dissolved in water? conducting is an electrolyte.
Ions are simply charged particles atoms or groups of? atoms. They may be positively charged cations. Or negatively charged anions.
The polar water molecules stabilize the ions as they? break apart ( dissociate).
Strong electrolyte water? is strong enough that it will pull all the ions a part until we have a homogenous solution.
Polyatomic ions? carbonate CO32-, hydroxide OH-, Sulfate SO42-, ammonium NH4+
Dissociates is to? break apart. Or is compounds that break into ions.
Compounds like sugar will dissolve but will not? dissociate.
Which of the following will not dissolve in water? C6H6.
Cadmium, Lead, Mercury pose as? health risks.
Filtration? filters out tree branches and big stuff from lakes. Flocculation add flocculation agents. Sand filter, chlorination. We can use ozone for treatment of water ( ozonenation), more expensive. Ozone decreases rapidly so want to use in smaller community.
Distillation a separation process in which a liquid? solution is heated and the vapors are condensed and collected. In distillation we boil it and condense it, best way to get pure water.
The troposphere is the lowest region of the atmosphere in which we? live. Weather also occurs in the troposphere.
Air is a mixture? a physical combination of two or more substances present in variable amounts. Can separate mixtures. Its a physical combination.
100 times carbon dioxide exhaled versus what we? breathed in because is combustion.
Water vapor is? the only compound that can vary significantly in air. Ex. water levels can be different.
Particulate matter PM? soot, black gas, smoke.
Cold air is more dense than? warm air. Cold air traps bad gases in valleys. Air inversion warm air comes in, causing cool air to drop.
Risk assessment? evaluating scientific data and making predictions in an organized matter about the probabilities of an occurrence.
Toxicity? intrinsic health hazard of a substance.
Exposure is the? amount of the substance encountered.
Two components of risk assessment? toxicity ( how bad the substance is) and exposure the amount of substance encountered and how long exposed to the substance (time).
If matter can be separated by a physical process then it is a? mixture, if cannot then it is a pure substance. With pure substances if it can be broken down into simpler ones by chemical means, then it is an element if not it is a compound.
Matter can be broken down in mixture and? pure substances.
Groups are? vertical columns. Periods only seven periods. Groups have similar properties, periods increase by atomic number.
A molecule is a fixed number of atoms held together by? chemical bonds in a certain spatial arrangement.
Atoms are the smallest unit of that? element but contains properties of that element.
Many nonmetals occur as? diatomic ( made up of two atoms) molecules.
Prefixes? mono-1, di-two, tri-3, tetra-4, penta-5, hexa-6, hepta-7, octa-8, nona-9, deca-10.
N2O is? dinitrogen monoxide ( laughing gas).
P2O5? diphosphorus pentoxide.
The hydrocarbons are? methane CH4, ethane C2H6, Propane C3H8, and Butane C4H10.
Chemical reactions are characterized by the? rearrangement of atoms when reactants are transformed into products.
But the number of atoms on each side of the arrow must be? equal ( Law of Conservation of Mass).
Combustion? The chemical process of burning; the rapid reaction of fuel with oxygen to release energy in the form of heat and light.
Processes and type of change? burning charcoal- chemical, food digestion chemical, freezing water physical, boiling water physical, cleaning oven with oven off chemical, fireworks chemical, forming syrup from sugar and water physical.
Socks are? sulfur oxides. Sulfur oxides come mostly from coal, some from gas and diesel.
Nocks are? nitrogen oxides. Nitrogen oxides from auto engines or coal fired power plant. Nocks from automobiles.
Catalytic converters reduce? amount of carbon monoxide.
Ozone in the troposphere is? bad since it is hazardous to our health; stratosphere ozone is good because protects us from UV radiation.
Indoor air pollutants are? acetone, incense, scentcies can be bad for your health. We do have indoor air pollutants. Carbon monoxide might be the most common air pollutant. To reduce indoor air pollutants use ventilation.
Ozone is an allotropic form of? oxygen.
An allotrope is two or more forms of the same? element that differ in their chemical structure and therefore their properties. Such as O2 and O3.
Ozone is in? the stratosphere ( ozone layer).
Dobson unit? 1 DU=3 X 10^16 O3 molecules in an atmosphere column of 1 cm^2.
Protons and neutrons reside in? nucleus. Neutrons have neutral charge, protons have positive charge, and electrons have negative charge.
Protons have a relative charge of? +1, Relative mass-1, Actual mass- 1.67 X 10^-27 kg. Neutron relative charge- 0, relative mass- 1, Actual Mass- 1.67 X 10 -27, Electron relative charge- -1, relative mass- 0, Actual Mass- 9.11 X 10 ^-33.
Atomic number is the number of? protons (nuclear charge).
Mass number is the sum? of the protons and neutrons.
To find neutrons subtract atomic number from? mass number. To find electrons it is the same number as protons to balance it. Protons are the atomic number. Mass number – atomic number = neutrons.
The electrons in the outermost energy levels are called? valence electrons. The group number ( of the representative elements) on the periodic table tells you the number of valence electrons.
When two electrons are paired its called a? single bond. 4 electrons are called a double pair. Lone pair electrons are electrons that do not pair.
Triple bond has? six molecules. Single bond two. Double bond four electrons.
Wave length distance? distance traveled between successive peaks (Nm). Frequency- how many cycles from one peak to another. Shorter the wave length, the higher the frequency, the longer the wave length the lower the frequency.
The Electromagnetic Spectrum? Shorter wave lengths to longer wave lengths- Gamma rays, X-rays, UV visible, IR, Microwaves, Radio. Long wave lengths to short wave lengths- Radio, microwaves, IR, UV Visible, X-Rays, Gamma rays.
What is the phrase to remember decreasing wavelength ROYGBIV.
Infrared ( IR) ? longest of the visible spectrum; heat ray absorptions cause molecules to bend and stretch.
Microwaves? cause molecules to rotate.
Short wave range? Includes UV radiation, X-Rays, and gamma rays.
Chapman cycle? the first set of natural steady state reactions proposed for stratospheric ozone.
The importance of ozone and oxygen is to absorb UV-A ,B? and C.
The most deadly form of skin cancer is? melanoma which is linked with the intensity of UV radiation and the latitude at which you live.
Ozone hole is more prominent over Antarctica due to? cold, ice crystals, more reactions on the ice surfaces there.
Cfcs largest contributor to? ozone depletion.
Free radical a highly reactive? chemical species with one or more unpaired electrons. These get in stratosphere, Uv breaks hydrogen and electrons like to be paired and shared in even numbers. Fluoro carbons rise to atmosphere and attacked by UV radiation.
As chlorine in atmosphere rises, our ozone? declines.
Montreal protocol in 1987? An international treaty for phasing out substances responsible for depleting the ozone layer.
HCFCs are alternatives to CFCs they decompose more? readily in the troposphere so they will not accumulate to the same extent in the stratosphere.
HFCs do not contain? chlorine.
Hydrofluoroolefin has? double bond, no hydrogen damage, HFO-1234yf. No chlorine and has double bond.
Greenhouse effect? our atmospheric gases trap and return a major portion of the heat radiating from the Earth. It is a natural necessary process.
Greenhouse gas? gases that absorb/ emit heat.
Industrial revolution?
Methane is 23 times more powerful than? CO2 as a GHG. Sources of methane include digestive systems of ruminants (cows, sheep, goats, etc.), rice cultivation, and decaying wetland vegetation.
Molecular shape of molecules is what? determines a greenhouse gas potential.
The 3D shape of a molecule affects its ability to absorb IR? radiation. Ir radiation is the heat.
The molecular geometry model ( molecule vibration model) and absorption of IR radiation with the? arrow on either side of the line only can not absorb UV radiation.
Infrared is less energy than? UV. UV can break bonds and infrared causes more bond vibration.
Any molecule that can vibrate with the? infrared radiation can be a greenhouse gas. The more bonds a molecule has, the more it can absorb, and more vibrations it has, the more it can release heat.
When atoms are the same, they can not absorb? infrared radiation diatomic.
Sequestration is? carbon absorbed in oceans, rocks, underground injection. Or ability to take in something. Trap carbon dioxide, example, of sequestration-reforestation.
A mole of atoms of any element has a? mass ( in grams) equal to the atomic mass of the element in amu.
To calculate molar mass? multiple the number of the element by the elements atomic mass. If a compound break it up and add the atomic masses and multiply the number of an element by an atomic mass if need to.
Global warming potential ( GWP) represents? the relative contribution of a molecule of an atmospheric gas to global warming.
What we know about the amplification of greenhouse effect? CO2 contributes to an elevated global temperature. The concentration of CO2 in the atmosphere has been increasing over the past century. The increase of atmospheric CO2 is a consequence of human activity.
More things we know about greenhouse effect and global warming? average global temperature has increased over the past century. Heat energy radiated by earth is captured by atmospheric molecules.
Weather is a set of all the phenomena occurring in a? given atmosphere at a given time. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally to day to day temperature and precipitation activity.
Climate is the long term pattern of weather and tracked based on two? meteorological characteristics; temperature and precipitation.
Climate change? is the changes observed in the long-term pattern of temperature and precipitation.
What to do with excess CO2? sequestration, reforestation, and CO2 reuse.
Kyoto Protocol-1997 Conference? Intergovernmental Panel on Climate Change ( IPCC) certified the scientific basis of the greenhouse effect. Kyoto Protocol established goals to stabilize and reduce atmospheric greenhouse gases.
Kyoto Protocol-1997 Conference Continued? Emission targets set to reduce emissions of six greenhouse gases from 1990 levels, ( CO2, CH4, NO, HFCs, PFCs, and SF6). Trading of emission credits allowed.
The Kyoto Protocol, an international and legally binding? agreement to reduce greenhouse gases emissions worldwide, entered into force on February 16 2005. US has not signed this treaty or Paris accord.
US is the biggest producer of? CO2 but also is the largest reducer.
Cap and Trade system? The trade part of the cap and trade system works through a system of allowances. Companies are assigned allowances that authorize the emission of a certain quantity of CO2 either during the current year or any year thereafter.
More with Cap and trade system? At the end of a year, each company must have sufficient allowances to cover its actual emissions. If it has extra allowances, it can trade or sell them to another company that might have exceeded their emissions limit.
If a company has insufficient allowances, it must? purchase them. The "cap" is enforced by creating only a certain number of allowances each year.
The cap and trade system has some possible? disadvantages including a potentially volatile market for the emissions permits. Energy providers might experience wide often unpredictable swings in their energy costs. Those swings would result in large fluctuations in consumer costs.
As an alternative to cap and trade some advocate? a carbon tax instead of a cap and trade program. Instead of limiting emissions and letting the market decide how best to comply, a carbon tax simply increases the cost of burning fossil fuels.
The best overall strategy for reducing CO2 is to? use alternate sources of energy.
Energy is the? capacity to do work.
Heat is energy that flows from a? hotter to a colder object. Heat is a consequence of motion at the molecular level.
Temperature determines the direction of? heat flow. Is a measure of the average speed of that motion.
What are the units of heat? joule : 1 J is the amount of energy required to raise a 1 kg object 10 cm against the force of gravity. Calorie : 1 cal is the amount of heat required to raise the temperature of 1 g of water by 1 C.
First law? The energy of the universe is constant, or energy can neither be created nor destroyed, but it can be converted from one form to another.
Kinetic is? motion.
Potential energy? is energy due to position or composition.
Kinetic energy? is energy due to movement.
Powerplants are? inefficient.
Power plant process diagram? power plant process- potential energy ( chemical bonds)-burner-kinetic energy-gas turbine-mechanical energy-generator-electrical energy.
The efficiency of powerplant in percentages is 35% to? 50%
Energy is released in a process called? combustion.
When energy is released during the course of a chemical? reaction it is said to be an exothermic reaction.
When given kilojoules and must convert to grams? multiply the kilojoules by 1000.
Activation energy is the energy required to initiate the? reaction.
Endothermic reactions will have products higher in? energy than the reactants; there will still be a required activation energy.
Bond energy is the amount of energy that must be? absorbed to break a chemical bond. Breaking bonds always requires energy.
Breaking bonds requires energy and? forming bonds releases energy.
Coal switching means we are going to an alternate? source of coal so we can meet the tighter standards trying to reduce sulfur oxides. Tries to switch to cleaner coal, switching to lower sulfur coal. Texas burns Wyoming coal. Wyoming coal is clean, called bituminous.
Last refinery was built in? 1976.
Crude oil mix of many? hydrocarbons. Hydrocarbons can go up to C-60.
Fractional distillation is how we? separate products, fractional distillation separates compounds.
Gasoline is the largest fraction we get from a barrel of? oil.
Cracking is making? smaller compounds. Reforming is taking small molecules and increasing them.
Octane rating is the resistance to? knocking; the higher octane means that their will be a higher resistance to knocking, we also add additives to prevent knocking as well.
Oxygenates help to reduce carbon? monoxide. At one time tetraethyl lead was used for octane ratings.
Fuel alternatives biodiesel? use is becoming more popular it is made from natural, renewable sources ( vegetable oils, animal fats), it can be used as pure fuel or blended with petroleum. It is non-toxic, biodegradable, and can be used in diesel engines.
Other fuel alternatives include? Ethanol is renewable but more expensive than gasoline. Some believe it takes more energy to produce a gallon of ethanol than you will obtain from burning it.
Other sources of energy to consider biomass is garbage? processing plant matter. Wind, solar- greatest potential for future energy needs.
One way to define an acid is as a substance that? releases hydrogen ions, H+ in aqueous solution. Since the hydrogen ion has no electron, and only one proton ( hence the positive charge), the hydrogen ion sometimes referred to as a proton.
Acid in aqueous solutions releases? hydrogen atoms. When we talk about strong acids have complete dissociation.
When dissolved in water, each HCl donates a proton? (H+) to an H2O molecule, forming H3O+, the hydronium ion. H3O+ added proton to water molecule so have lone electron pair left.
A base is any compound that produces hydroxide? ions (OH-) in aqueous solutions. OH- ( aq) hydroxide ion gives rise to base. Characteristics properties of bases: bitter taste, slippery feel when dissolved in water, turn red litmus paper blue.
Dissociation? is to break a part. Compounds into ions.
When acids and bases react with each other we call this a? neutralization reaction. In neutralization reactions, hydrogen ions from an acid combine with the hydroxide ions from a base to form molecules of water. Products of neutralization water and salt.
Acidic solutions contain a higher concentration of H+? ions than OH- ions. Basic solutions contain a higher concentration of OH- ions than H+ ions.
The higher the PH more basic? the lower the PH the more acidic. Lower PH numbering / less than 7 more acidic. Greater than 7 more basic.
Normal rain is slightly? acidic.
Carbon dioxide in the atmosphere dissolves to? a slight extent in water and reacts with it to produce a slightly acidic solution of carbonic acid. The carbonic acid dissociates slightly leading to rain with a PH around 5.3 or 5.2.
Carbon dioxide in atmosphere reacts with water in? atmosphere to form carbonic acid ( weak) acid. Weak acids do not completely dissociate.
Analysis of rain for specific compounds confirms that the chief culprits are the oxides of sulfur and nitrogen? Sulfur dioxide ( SO2), sulfur trioxide (SO3), nitrogen monoxide (NO), and nitrogen dioxide ( NO2). These compounds are known as SOx and Nox.
Sulfur dioxide emissions are highest regions with many? coal fired electric power plants, steel mills, and other heavy industries that rely on coal.
How does sulfur get into the atmosphere? the burning of coal. Coal contains 1-3% sulfur and coal burning power plants usually burn about 1 million metric tons of coal a year. Coal fired power plants contribute 85% of our sulfur dioxides.
To reduce sulfur dioxide and sulfur trioxide use? coal switching which means switching from Pennsylvania coal to Wyoming coal which has less sulfur in it.
SOX decreasing a lot more better than Noxs since? SOx originate from coal but now we are using natural gas and switching to cleaner coal which lessens the SOx.
Nitrogen oxide in atmosphere and acid rain are? affecting our painted objects such as cars and statues, it erodes them.
Midwestern lakes contain a lot of limestone? CaCO3. Co3-2, HCO3- ions react with H+, northeastern lakes contain mostly granite very impervious to acids.
Granite more impervious to? acids than limestone.
A battery is a system for the direct conversion of chemical energy to? electrical energy. Batteries are found everywhere in today's society because they are convenient, transportable sources of stored energy. The batteries shown here are more correctly called galvanic cells.
A series of galvanic cells that are wired together constitutes a? true battery like the one in your car. Batteries are systems of galvanic cells.
A galvanic cell is a device that converts the energy? released in a spontaneous chemical reaction into electrical energy. This is accomplished by the transfer of electrons from one substance to another. Electricity is the flow of electrons.
The electron transfer process involves two changes? oxidation and reduction. Each process is expressed as a half reaction.
The overall cell reactions does not have any electrons? written on it, they must cancel. Half reaction-one species is gaining electrons, one species is losing electrons.
Rechargeable battery ( galvanic cell) ? NiCad is a rechargeable battery. Battery gets energy back after getting plugged in. Chemical reaction is reversible.
Oxidation is the? loss of electrons. Reduction is the gain of electrons.
Electrodes ( electrical conductors) are placed in the cell? as sites for chemical reactions. Reduction occurs at the cathode, the cathode receives the electrons. Oxidation occurs at the anode. Anode is negative side of battery and the cathode is positive side of battery.
The difference in electrochemical potential between the? two electrodes is the voltage ( units are in volts).
Salt bridge enables connections between the two cells and allows for the? transfer of anions.
For cellphones etc., battery must be? lightweight, run for a reasonable time, needs to have good potential ( good voltage), do not necessarily want fully liquid batteries, want fairly solid battery.
What type of reaction for rechargable battery? reversible reaction.
Alkaline galvanic cell does not have what type of battery because? chemical reaction is not reversible because does not have a reusable battery.
Uses an alternator in vehicle to recharge? the battery. Disadvantage it is a heavy battery.
Hybrids run on both gasoline and? electric motor to help reduce carbon dioxide.
Two big advantages of hydrogen cell is that water is one? of the products and we can get power from it as long as oxygen is flowing and hydrogen keeps flowing in because no motor is in the cell so oxygen keeps flowing to power it. Hydrogen and oxygen need to flow into cell.
Fuel cell must remain moist in order for that reaction to? occur it cannot dry out. Must also remain cool. Has to be less than 100 degrees Celsius.
Safety hydrogen is very? combustible. Hydrogen is not found naturally anywhere on earth. Distribution is not common to run across the hydrogen gas stations. It is a lightweight element and can leak so must use airtight system cannot have any leaks.
If the hydrogen economy becomes reality where will we get the H2? hydrogen and oxygen produced by the electrolysis of water. But this process requires energy. Hydrogen takes a lot of power. Hydrogen not available naturally. Expensive to generate and hard to transport.
Solar panels convert sunlight directly into? electricity and we typically use this energy to power highway signs,homes, buildings, and some calculators.
Thin layers of silkin wafers are called? photovoltaic cells and has light voltage/ electricity.
Doping impregnable the? silkin. Adding arsenic and gallium to silkin to get electron flow.
Examples of synthetic polymers? rayon, nylon, lycra, polyurethane, Teflon, Styrofoam, saran.
Polymers are large molecules made up of long chains of? atoms covalently bonded together. Monomers are the small molecules used to synthesize the polymeric chain like a strand of paper clips. Plastics are pliable/ movable. Link monomers together to form polymers.
Natural polymers include such things such as? cellulose, starch, tar, shellac, tortoise shell and horns, as well as tree saps that produce amber and latex. Natural polymers wool, rubber, proteins, and starches.
Polymers are referred to as macromolecules because they? involve thousands of atoms and their molecular masses can reach over a million. Many common classes of polymers are composed of hydrocarbons.
Hydrocarbons? methane, ethane, propane, butane. Crude oil is the largest source for our monomers which we use to make polymers. Crude oil is most convenient and economic material for polymers.
In addition polymers, the monomers simply add to the growing? polymer chain in such a way that the product contains all the atoms of the starting material.
To make polymers use addition and? the other process elimination. Ethylene monomer is the double ( two carbon) bonded carbon with the four hydrogens.
Polyethylene is a commonly produced what? polymer in the United States.
What does necking polymers mean? being able to stretch. Dispersion forces ( intermolecular forces) are attractions between molecules in the polymer that hold the material together.
HDPE is the? high density make a lot of containers out of HDPE. Linear makes high density, branches make low density.
Here are the three of the most common polymers known? collectively as the big six; polyethylene (LDPE), polyethylene ( HDPE) Polyvinyl chloride, polystyrene, polypropylene, polyethylene terephthalate.
Polyethylene ( LDPE) properties and uses? translucent if not pigmented, soft and flexible. Unreactive to acids and bases. Strong and tough. Uses- bags, films, sheets, bubble wrap, toys, wire insulation.
Polyethylene (HDPE) properties and uses? similar to LDPE. More rigid, tougher, slightly more dense. Uses- opaque milk, juice, detergent, and shampoo bottles. Buckets, crates, and fencing.
Polyvinyl chloride properties and uses? Variable. Rigid if not softened with a plasticizer. Clear and shiny, but often pigmented. Resistant to most chemicals, including oils, acids, and bases. Uses- rigid- plumbing pipe, house siding, charge cards, hotel room keys.
Polyvinyl chloride softened uses? garden hoses, waterproof boots, shower curtains, iv tubing.
Examples of vinyl chloride? pvc, shower curtains, house siding, room keys for hotels, hoses, iv tubing. Polyvinyl chloride must be separated from other products because when getting heated will give off hydrogen chloride.
Polystyrene properties? variable. "Crystal form" transparent, sparkling somewhat brittle. Expandable form lightweight foam. Both forms rigid and dissolve in many organic solvents.
Polystyrene uses? crystal form, food wrap, CD cases, transparent cups, expandable form: foam cups, insulated containers, food packaging trays, egg cartons, packaging peanuts.
Polypropylene properties? opaque, very tough, good weather ability. High melting point. Resistant to oils. Uses- bottle caps, yogurt, cream, and margarine containers, carpeting, casual furniture, luggage.
Polyethylene terephthalate properties? transparent, strong, shatter resistant, impervious to acids, and atmospheric gases. Most costly of the six. Uses- Soft-drink bottles, clear food containers, beverage glasses, fleece fabrics, carpet yarns, fiber fill insulation.
Big six polymers are called? thermal plastics. Polyethylene terephitlate has two molecules ethylene glycol and terephthalic acid condense so process is called condensation. Ethylene glycol and terephthalic acid in polyethylene terephthalate combine form H20 molecule.
Polystyrene packaging and? an ice chest are examples of what we call the expanded polystyrene.
Condensation polymerization? instead of addition polymerization, some monomers crosslink together by eliminating a small molecule such as water. Most natural polymers are formed by condensation polymerization including starch, cellulose, wool, silk, and proteins.
The polymer PETE ( polyethylene terephthalate) and two polymers form a? H2O molecule. PETE ( polyethylene terephthalate ) polymers are called co-polymers.
Peptide bond? covalent bond that forms between COOH group of one amino acid and the NH2 group of the next. The peptide bond has an oxygen , two carbons, and a nitrogen.
Bottle bill states? these states that have a deposit on plastic bottles.
Incineration we can burn some plastic and polymers? and can get energy from that. Source reduction is the most preferred and means uses less polymers in the first place.

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