## Chemistry

 The volume of gas is affected by a change in what two things?
 pressure and temperature
 Gases have relatively low ________ and low ______.
 density/viscosity
 G
 Gases are miscible. What does this mean?
 That they mxi easily with other gases.
 What are the four units of pressure? And how are they all related?
 atmospheres; torr; mmHg; Pascals   1 atm=760 torr=760 mmHg=1.01E5 Pa
 What is included in the ideal gas equation PV=nRT
 pressure (atm) volume (L) number of moles R (constant) .08206 atm-L/mol-K
 What are the rules for R as a constant as far as when to use it and what are each of the values?
 R for pressure (atm/torr) .08206 atm-L/mol-K   R for energy (heat/energy) 8.314
 What is Boyle’s law?
 V1P1=V2P2 ; volume and pressure are indirectly proportional
 What is shown in Charle’s Law?
 volume is proportional to temperature
 that volume is proportional to the number of moles
 What does STP stand for? what what are the values?
 standard temperature and pressure ; T= 0 degrees celsius 273.15 K ; P= 1 atm ; standard molar volume: 22.4 L
 What is the definition of standard molar volume?
 one mole of any gas will occupy 22.4 L at STP. ; (depends on number of moles… it may double or triple)
 State the law of partial pressures:
 for a mixture of non-reacting gases, the total pressure is the sum of the partial (of individual) pressures for each gas
 what theory allows us to derive certain equations regarding the motion of indivudal gas particles?
 kinetic-molecular theory, KMT
 KMT looks at the _________ in energy of the gas molecules
 changes
 Increasing temperature casues an increase in ________?
 energy
 What causes the average velocity and the collisions to increase?
 increasing temperature
 In the kinetic energy equation, which R is used?
 R= 8.314 J/mol-K
 the process in which a gas escapes (of leaks) from its container through a small hole
 effusion
 what is the law of effusion for an ideal gas?
 the rate of effusion of a gas is inversely proportional to the square root of its molar mass
 The rate of effusion compares what?
 what rates of effusion between two different gases, A and B
 Can the rate of effusion equation be replaced to solve for time?
 most definitely
 What is the motion of one gas moving through another gas?
 diffusion
 at a given temperature, the energy and the speed of a molecule is inversely proportion to what? ; (rate of effusion equation)
 mass
 What value for R is used in the root-mean-square equation?
 R= 8.314 J/mol-K
 IDEAL GASES: -work best as ____ pressure and ____ temperatures -assumes no ________ ______ -assumes no ______ ______
 low/high intermolecular interaction molecular volume
 REAL GASES: -molecules have _______ size and occupy ______ -molecules have _______ forces that become significant when they are in close proximity -at ______ pressures attractive forces lead to the appearance of fewer ______ -at very _____ pressure the finite volume of molecules causes repulsion and leads to the appearance of more ____
 finite/space attractive high/moles high/moles
 in the real gas equation: ; pressure values are adjusted to account for…? ; what is the constant? ;
 attractive interactions of intermolecular forces ; a
 in the real gas equation: ; volume is adjusted to account for the…? ; what is the constant?
 finite volume, molecular shape and the increased frequency of collisions ; b
 who proposed the real gas equation?
 van der waals
 what two components make up a majority of the earth’s atmosphere?   in what proportions (%volume and mole fraction)
 nitrogen N2 78.084% .78084   oxygen O2 20.948% .20948
 what does the pressure at a given altitude depend on?
 thew eight of the gases above it
 at a lower altitude the pressure is greater.   why?
 because there is more gas above
 pressure decreases and what increases?
 altitude.
 temperature in the atmosphere results from gas molecules ______ the sun’s high energy ______.
 the absorption causes molecules to ?
 ionize
 warming is caused by the _______ cycle.
 ozone
 ozone absorbs what kind of light?
 ultraviolet light
 in photodissociation, how much energy is required to break O2 bonds?
 495 kJ/mol
 the concentration of O2 ________ as altitude increases.
 decreases
 ozone: – ___ resonance forms – ____ stable than O2 -_____ bond length than O2 -Bent angle at ____degrees -what color?
 2 less longer 117 light blue gas
 what is the primary benefit of ozone?
 it protects us from dangerous UV radiation
 how many reactions are needed to form ozone? ; how many reactions are needed to destroy ozone?
 2 ; 1
 what destroys ozone?
 CFCs
 where do CFCs diffuse to?
 the upper atmosphere
 when CFCs undergo photodissociation, what is released?
 chlorine atom
 what has replaced CFCs?
 HFCs
 what is the lowest portion of earth’s atmospher?
 troposphere
 energy coming into the earth is mostly?
 solar
 what percentage of energy is reflected by the atmosphere?
 30%
 what type of energy is absorbed by the atmosphere?
 UV
 Most of the radiation hits earth’s surface and is absorbed. what does this cause?
 warming
 earth’s surface radiates ehat back into the atmosphere in the form of ________ heat.
 infrared
 what absorbs infrared heat?
 H2O, CO2, CH4, O3
 what gases in thermal regulation lead to the greenhouse affect?
 carbon dioxide   water
 what are the three states of matter?
 solid, liquid, gas
 Solid state: -_________ force between the particles is far _____ than the ________ _____ of the particles.
 attractive/greater/kinetic energy
 solid state:   -particles remain in _______ -solid has a ______ shape -no _______ -no _____ ___ _____   stronger IF’s mean…
 -position -specific -compressibility -ability to flow ; higher melting point
 Liquid state: ; ________ _____ of the particles is ______ than those in a solid but still weaker than the ______ ____
 kinetic energy stronger attractive force
 liquid state: ; ___ = ____
 IF = KE
 liquid state: ; -kinetic energy allows for particles to ____ ____, but remain in virtual _____ -very low ______ -moderate ____ __ ____
 tumble randomly/contact compressibility ability to flow
 liquids with strong IF will have what?
 higher boiling points
 Gas State: the _____ ____ of the particles is stronger than _____ _____ ; -occupy the shape of the _____ ; -high _______ -high _____ __ ____
 kinetic energy attractive forces ; container ; compressibility ability to flow
 solid —> liquid   endo or exo?
 melting/fusion   endo
 liquid —-> gas   endo or exo?
 vaporization   endo
 solid —> gas   endo or exo?lo
 sublimation   endo   ** at low pressure
 gas —> liquid   endo or exo?
 condensation   exo
 liquid —> solid   endo or exo?
 freezing   exo
 gas —-> solid   endo or exo?
 deposition   exo
 what are the delta H symbols?   liquid and solid…   liquid and gas…   solid and gas…
 fus   vap   sub
 definition:   the amount of heat needed to change the temperature of 1 gram of a substance by 1 Kelvin
 specific heat capacity
 specific heat capacity is _____ for every compound in every ______/
 unique/phase
 what specific heat capacity is replaced by molar heat capacity, what are the units?
 J/mol-K
 Phase change:   during a phase shift, the ______ remains constant and all heat energy changes result from either _______ or ____ the _____ between the molecules within the substance
 temperature forming/breaking bonds
 in the phase change from a gas to liquid or liquid to solid: the energy is _______ as molecules _____ bonds.
 released/form
 during phase changes from solid to liquid or liquid to gas, the energy is ____ and molecules _____ bonds.
 absorbed/break
 energy changes are calculated using:
 delta H: fusion delta H: vaporization
 what is the first law of thermodynamics?
 energy cannot be destroyed or created, only transferred
 the amount of heat lost by a system ____ the amount of heat gained by the surroundings
 equal
 what are the two most common types of calorimeters?
 bomb calorimeters   coffee cup calorimeters
 the rate of vaporization is greater than the rate of condensation. which causes for what to happen?
 molecules break free from the surface of water and enter the gas phase
 what will increase as more and more gaseous water molecules leave the surface?
 pressure of the water vapor in the container
 does the pressure eventually reach a maximum?
 yes.
 what causes for there to be a maximum in pressure?
 the fact that the rate of vaporzation is now equal to the rate of condensation
 when the rate of vaporization is now equal to the rate of condensation, what does this actually mean?
 the same amount of water molecules are leaving the surface as there are joining the surface
 a system is in equilibrium when…
 the same amount of water molecules are leaving the surface as there are joining the surface
 what happens when liquid’s vapor pressure reaches the external pressure (usually atmospheric pressure)?
 it boils
 the boiling point at atmospheric pressure, 1 atm?
 normal boiling point
 at higher altitudes, water will boil at a _____ temperature
 lower
 what causes for more molecules in a liquid to escape to the gas phase?
 higher temperature
 what two major factors affect vapor pressure?
 temperature and intermolecular forces
 temperature: -raising the temperature increases the _____ ____ of the molecules, making it easier for them to escape from the ______, and harder for them to _______.   -in general, the higher the temperature, the higher the ______ _______
 kinetic energy/surface/return   vapor pressure
 intermolecular forces: -these are the _____ ____ that keep particles ______. Weake intermolecular forces allow the particles to _______ more easily.   -in general, the weaker the intermolecular forces, the higher the ______ _____.
 attractive forces/together/vaporize   vapor pressure
 what two factors affect the phase of a substance?
 pressure and temperature
 what is the point at which all three phases are in equilibrium?
 triple point
 what is the point called where the liquid/gas line ends?
 critical point
 at the critical point, the liquid and vapor pressure are ______.
 equal
 beyond the critical temperature, what exists?
 supercritical fluid
 for normal compounds, an increase in pressure will result in the phase change of liquid to solid, like CO2.   Why is this?
 because the solid is denser than the liquid
 why is the line screwed up for H2O in the phase diagram?
 because water is denser than ice
 what is a solution?
 a solute dissolved in a solvent
 the maximum amount that can be dissolved into a fixed amount of a specific solvent at a given temperature.   what is this?
 solubility of a solute
 what are the six intermolecular forces?
 1. ion-dipole (ion-polar) 2. dipole-dipole (two polar molecules) 3. hydrogen bonding (H-NOF) 4. ion-induced dipole (ion-nonpolar) 5. dipole-induced dipole (polar-nonpolar) 6. dispersion (London) (nonpolar-nonpolar)
 intermolecular forces directly affect…
 solubility
 common solution:   _____ solvents ______ or ______ solutes
 liquid liquid/solid
 what does “like dissolves like” mean?
 substances with similar types of intermolecular forces are more likely to dissolve in each other
 solubility:   -ions and polar molecules will readily dissolve into ______ solvents   -nonpolar molecules will readily dissolve into ______ solvents
 polar    nonpolar
 when a solution is formed, energy is either ______ or ______.   which is measures by a change in ______.
 released/absorbed   enthalpy
 enthalpy   solute particles separate solvent particles separate solute and solvent mix
 endo endo exo
 what must be added together in order to find the enthalpy of the solution?
 the enthalpy of the solute, solvent, and mix
 what does it mean if the change in H is positive?
 the process is endothermic and the solute won’t dissolve well in the solvent unless change in entropy is very high
 What does it mean if change in H is negative?
 what is it called when solvent particles surround a solute particle?   what is this called in water?
 solvation   hydration
 when a solution is forming, solute particles break apart from one another and become dispersed in the solvent. but what can happen on occasion?
 the solute particles collide with undissolved solute and recrystalize
 rate of dissolving at first is faster than the rate of…
 recrystalizing
 when the rate of dissolving and the rate of recrystalizing occur, they will eventually even out which is called the
 equilibium
 if a solution contains the maximum amoutn of dissolved solute particles at a given temperature, it is considered…
 saturated
 what if it has less than the maximum amount of dissolved solute particles?   what if it has more?
 unsaturated   supersaturated
 temperature and solubility:   for solids, increasing temperature ______ solubility.   for gases dissolved in water, increasing temperature ______ solubility.
 increases   decreases
 pressure and solubility   -as pressure increases, the solubility of a gas _______
 increases
 what is the amount of solute present within a given volume of the solution?
 concentration
 how is molarity expressed?
 M   moles of solute/Liters of solution
 when diluting, what changes?
 volume
 what are 5 ways to express concentration: the proportion of a substance in a mixture?
 1. molarity (M) 2. molality (m) 3. parts by mass 4. parts by volume 5. mole fraction (x)
 what are concentrations measured in if they are very small amounts?
 ppm and ppb
 solutes that are cpaable of dissociating are often called…
 electrolytes
 strong electrolyate dissociate ______ in water and are _____ conductors of electricity.
 completely/good
 weak electrolyate only dissociate _____ and are _____ conductors.
 partially/poor
 nonelectrolyates do not _______ in water and are ________.
 dissociate/non-conductors
 if a water soluble comound is ionic, then it is definitely a…
 strong electrolyte
 not all electrolyates are ionic compounds…   true or false
 true
 ionic compounds are only good conductors if the compound is …
 soluble
 colligative properties are ________ properties.
 physical
 colligative properties depends on the _______ of solute particles dissolved in a given solvent.
 number
 the four types of colligative properties that can affect a solution are:
 1. vapor pressure lowering 2. osmotic pressure changes 3. boiling point elevation 4. freezing point depression
 lowering vapor pressure   -the vapor pressure of a solution is always ______ than that of the pure solvent   -what law proves this?
 lower   Raoult’s Law
 boiling point increase   a solution has a _______ boiling point than the pure solvent
 higher
 freezing point decrease   -a solution freezes at a ______ temperature than a pure solvent
 lower
 Van”t Hoff Factor, i -refers to how the amount of ______ _____ can increase if the solute itself i able to ______ into its constituent ions. -______ that are capable of _______ in solution are often called ________
 solute particles/dissociate   solutes/dissociating/electrolytes
 osmotic pressure   -known also as ______ pressure -it is produced by a solution with a ________ in the concentration of solute   — Van’t Hoff factor refers to how the mount of solute particles ______ by a ________ factor if the solute is an ionic compound and _______ into its _________ ions.
 hydrostatic   differential   increases/specific/dissociates/constituent
x

Hi!
I'm Anna

Would you like to get such a paper? How about receiving a customized one?

Check it out