General Chemistry Mcat 2

Front 1

1) How to determine how many electrons per shell in Bohr model?
2) What happens for an electron to be promoted to an excited state?

Back 1

1) 2n^2
2) It absorbs energy

Front 2

1) Explain effective nuclear charge
2) Explain the desire of an alkali metal and it's reactivity

Back 2

1) Nuclear charge - shielding electrons, the higher is is, the more stable it is. It has a higher ionization energy and can't be knocked off easily
2) to lose it's electron to be more stable, very reactive(low ionization E) -> more reactive as you go down b/c of increasing radii

Front 3

What do an alkali and alkaline earth metals form when they react with:
1) Oxygen
2) Water
3) Acids

Back 3

1) Oxides
2) Hydroxides and release H
3) Salts and release H

Front 4

1) Are halogens more reactive going up or down the P table?
2) Explain the reactivity of noble gases
3) T or F: The 2nd ionization E is always higher that the 1st

Back 4

1) Up b/c the radii decreases allow the desired electron to be accepted more easily
2) not reactive
3) T

Front 5

1) ionization trend?
2) electron affinity trend?
3) electronegativity trend?

Back 5

1) increases up & right
2) increases up & right
3) increase up & right

Front 6

1) What eqn measures the magnitude of an ionic bond?
2) Coulomb's law?
3) This law is analogous to what other law?

Back 6

1) Electrostatic E= |kq1q2/r|(the greater this value, the stronger the ionic bond)
2) F = kq1q2/r^2
3) The universal law of gravitation (F=Gm1m2/r^2)

Front 7

In K & C:
1) What is absolute zero?
2) What is the melting pt of ice?
3) What is room temperature?
4) What is our body temperature?
5) At what temp does steam condense?
6) What is the eqn for K and C conversion?

Back 7

1) K=0, C= -273
2) K=273, C=0
3) K=298, C=25
4) K=310, C=37
5) K=373, C=100
6) K = C + 273

Front 8

1) What is the eqn for pressure?
2) What amt of pressure does the atmosphere exert at sea level?
3) What is this number in: mmHg, kPa, Pa, Torr
4) Ideal gases occupy _____ L/mol

Back 8

1) P = F/A
2) 1 atm
3) 760mmHg, 101 kPa, 101,000 Pa, 760 Torr
4) 22.4

Front 9

1) When doing an P=F/A calculation, make sure F is in __(a)__ and A is in __(b)__
2) What unit will the result be?
3) Explain Avogadro's number

Back 9

1) F: N, A: m^2
2) Pa
3) It is the number of molecules per mol: 6.02E23

Front 10

What are the four requirements of an ideal gas?

Back 10

1) Random motion
2) Negligible molecular volume
3) Perfectly elastic collisions (conserve KE)
4) No intermolecular interactions

Front 11

1) What is the Ideal Gas Law?
2) What is the combined gas law?
3) What is the difference b/t Boyles Law and Charles Law?

Back 11

1) PV = nRT
2) (P1V1/T1) / (P2V2/T2)
3) Boyles law shows that if Temp was constant, P1V1=P2V2
Charles law shows that if Pressure was constant, T1/V1=T2/V2

Front 12

Kinetic Theory:
1) What causes pressure of a gas in a container?
2) How is pressure evenly distributed over the container?
3) Explain the relationship b/t T & KE

Back 12

1) Pressure is determined by how often the molecules hit the sides of the container
2) B/c random motion is occuring
3) As T increase, so does KE

Front 13

1) What is Graham's Law?
2) If one light gas & one heavy gas diffuse down a tube from opposite ends, where will the gases meet?
3) At what P & T are molecules ideal? (low vs high)

Back 13

1) (Rate1/Rate2) = √M2/M1
Rate is the rate of diffusion or effusion
2) The gases will meet closer to the side of the heavy gas b/c light gases move faster. At constant T, KE is conserved, ½m1v1^2 = ½m2v2^2
3) High T, Low P

Front 14

What is the Van der Waal's Eqn

Back 14

P = (nRT/V-nb) - (n^2a/V^2)

-The greater b, the more repulsion -->leads to more P
-The greater a, the more attraction-->less P

Front 15

1) What is Dalton's Law?
2) What is H bonding?
3) Do ethers form H bonds with other ethers?
4) The more polar a bond, the (stronger or weaker) the H bond. Which is strongest and weakest out of the H bonds?

Back 15

1) The total P exerted by a mixture = sum of partial pressures of individual gases
2) Bonding b/t an O, F, or N and an H
3) No, b/c ethers do not have a partially positive H (donor)
4) Stronger, H-F is strongest, H-N is weakest

Front 16

1) Do H bonds increase or decrease BP?
2) Do dipole-dipole interactions increase or decrease BP?
3) What forces are predominant in non-polar molecules? Polar molecules?

Back 16

1) Increase
2) Increase but not as significantly as H bonding
3) Non: Dispersion/Van der Waals, Polar: Dipole

Front 17

1) What is an induced dipole?
2) What is an instantaneous dipole?
3) Dispersion forces get stronger with smaller or larger molecules?

Back 17

1) When a polar molecule interacts with a non-polar molecule, then polar molecule induces a dipole in the non-polar molecule
2) Non-polar molecules have randomly fluctuating dipoles that tend to align with one another from one instant to the next
3) Larger

Front 18

Phase Diagram:
1) What is the triple point?
2) What is the critical pt?
3) What is the critical temp?
4) Why is the water phase diagram different from others?

Back 18

1) Pt at which all three phases exist
2) Point at which you can't distinguish b/t gas and liquid
3) Point at which you can no longer get a liquid no matter how much P is used
4) The solid phase line is more the left. This is b/c the liquid is more dense than the solid - so if you increase the pressure at a specific T, you turn ice into water

Front 19

1) What is molality?
2) What is the symbol for molality?
3) Define colligative properties
4) Adding solute raises the __(a)__ and lowers the __(b)__

Back 19

1) The measure of the concentration of solutes in a solution (mol/mass, kg, of solvent)
2) m (in comparison to molarity, M)
3) Properties that depend on the # of solute particles, but not on the type
4) (a) BP (b) FP

Front 20

1) Colligative properties take the _______ factor into consideration, which is _____
2) What is Raoult's Law? Explain eqn

Back 20

1) Van't Hoff Factor: Tells the total number of particles in a solution (glucose: 1, NaCl: 2, etc.)
2) ΔP = χsolute·P°solvent
χsolute: # mols of solute / # total mols of both solute and solvent (take Van't Hoff Fctr into account)
P°solvent: the vapor pressure of the pure solvent alone

Front 21

1) What is the eqn showing BP elevation?
2) What eqn shows freezing pt depression?
3) Osmotic P eqn?
4) What is osmosis?
5) What is osmotic P?

Back 21

1) ΔTb = kb·m·i
kb is the molal BP constant
2) ΔTf = -kf·m·i
3) π = MRT *i
4) Mvmnt of solvent across a semi-permeable membrane from low to high C
5) The P causing osmosis to occur, the pull of the solvent, it determines whether and in what direction osmosis will occur

Front 22

1) What are colloids? Ex.?
2) What is Henry's Law?

Back 22

1) Not a solution, but a mixture that can stay together until centrifuged (ex. milk, water & oil mixed vigorously)
2) Psolute = k [solute] (The partial pressure of a solute just above the solution's surface is directly proportional to its concentration.)

Front 23

1) What is the molecular mass (amu) of C?
2) Density units?
3) Eqn for specific gravity?
4) Units of specific gravity?

Back 23

1) 12amu (1amu = 1g/mol)
2) mass/volume (kg/m^3)
3) density of the substance/density of water
(density of H2O=1g/mL)
4) No unit

Front 24

1) When can disproportionation occur?
2) What is the eqn for free energy?
3) What are the units of entropy?

Back 24

1) When a species undergo both oxidation & reduction in one rxn (ex. Cu simultaneously acting as a reducing and oxidizing agent)
2) ΔG = ΔH - TΔS
3) J / K (energy/temp)

Front 25

What is the difference b/t an isolated system, closed system, and an open system?

Back 25

Isolated: No exchange of heat, work or matter w/surroundings
Closed: Exchange of heat and work, but not matter
Open: Exchange of heat, work, and matter

Front 26

1) What is a state function?
2) Give three examples
3) What is the specific heat of water?
4) 1 Calorie = __(a)__ calorie(s) = __(b)__ J

Back 26

1) Path-independent, only depends on start & finish
2) ΔH (enthalpy), ΔS (entropy), ΔG (free energy change), ΔU (internal energy change)
3) 4.184 J/g*k
4) (a) 1000 (b) 4200

Front 27

1) What is enthalpy?
2) What is the unit of enthalpy?
3) What is Hess' Law of heat summation?
4) A change in 1K is the same as a change in __ C

Back 27

1) The standard heat content of a rxn
2) J
3) total enthalpy change during the complete course of a reaction is the same whether the reaction is made in one step or in several steps
4) 1

Front 28

1) What is the 0th law of thermodynamics?
2) First law?
3) Second law?
4) The unit of any type of energy?

Back 28

1) Heat flows from hot to cold objects to achieve thermal equilibrium
2) ΔE = q + w, conservation of energy
3) Entropy - disorder is preferable
4) Joules

Front 29

Difference b/t conduction, convection, and radiation

Back 29

Conduction: heat transfer by direct contact
Convection: heat transfer by flowing current
Radiation: heat transfer by electromagnetic radiation

Front 30

1) What is the heat of fusion?
2) The energy it takes to melt a solid is ___ * ____
3) Where is W on a PV graph?

Back 30

1) Energy input needed to melt something from solid to liquid constant temperature
2) Hfus * mols of solid
3) the area under the curve

Front 31

1) Adiabatic process?
2) Eqn for specific heat determination?
3) Why does this eqn not work across phase changes?
4) Can you isolate the transition state of a rxn?

Back 31

1) No change in temp q = 0, ΔE = W
2) q = mcΔT
3) B/c different phases require different amts of E
To do probs w/phase change - do eqns separately, then compare
4) No, don't confuse this w/a rxn intermediate

Front 32

1) What is the activation energy?
2) What is the Arrhenius eqn?
3) Based on this eqn, what does low Ea and high T tell us?
4) Do enzymes effect kinetics or thermodynamics?

Back 32

1) The energy is takes to push reactants up to the transition state
2) k = Ae^(-Ea/RT)
A & R are constants
3) There will be a large k, faster rxn
4) Kinetics, Catalysts/enzymes increase k (rate constant, kinetics), but does not alter Keq (equilibrium)

Front 33

1) What are the two ways of getting the eq. constant, Keq?
2) What is the eqn showing the relationship b/t standard free energy and the eq. constant?
3) What is solvation?

Back 33

1) From an equation, Keq=([C]^c[D]^d)/([A]^a[B]^b)
or from thermodynamics, ΔG° = -RT ln (Keq)
2) ΔG = ΔG° + RT ln Q
3) Water forms a "shell" around ions in solution
(H+'s surround anions, etc)

Front 34

Difference b/t the common ion effect and the complex ion effect

Back 34

The common ion effect shows that (for ex.) if more Cl- is added to a solution, less AgCl would dissolve, and the complex ion effect shows that if a metal is added that can form a complex ion with Cl- (to "get rid of it"), then more Ag Cl could dissolve

Front 35

1) Difference b/t a Lewis acid and a Bronsted acid?
2) Kw = ?
3) pH eqn?
4) pH + OH = ?

Back 35

1) Lewis Acid Accepts e-'s & Bronsted Acid Donates H+
2) Kw = [H+][OH-] = 10^-7 * 10^-7 = 10^-14
3) pH = -log(H+)
4) 14

Front 36

1) What are the strong acids?
2) What are the strong bases?

Back 36

1) HCl, HBr, HI, H2SO4, HNO3, HCLO4, H+(H3O+)
2) LiOH, NaOH, KOH, RbOH, SOH, Ca(OH)^2, Sr(OH)^2, Ba(OH)^2

Front 37

1) How do protons exist in solution?
2) pKa + pKb = ?
3) pKa = ?

Back 37

1) H3O+, not H+
2) 14
3) -log(Ka)

Front 38

1) How do electrolytes conduct electricity?
2) What occurs if electrolytes are not present?
3) Units of current?
4) Eqn for Faraday's constant?

Back 38

1) By the motion of ions
2) W/out electrolytes, there won't be a circuit b/c electricity won't be able to travel
3) Coulombs of charge/second (I = q/t)
4) F = q/n (coulombs of charge per mol of electron)
(combining 3 & 4, you get It = nF)

Front 39

Describe the reduction potentials of these:
1) Cl2 + 2e- --> 2Cl-
2) 2H+ + 2e- --> H2
3) Na+ + e- --> Na

Back 39

1) +1.359 (Cl2 wants to become Cl-, it wants to be reduced)
2) 0
3) -2.714 (Na+ wants to remain in that state, it doesn't want to be reduced)

Front 40

1) In a galvanic cell, e-'s always flow from the ______ to the _____
2) Difference b/t a galvanic/voltaic cell and an electrolytic cell

Back 40

1) Anode to the cathode
2) In a galvanic/voltaic cell there is a natural flow of electrons, the molecule that with the highest oxidation pot. are placed with the anode and vice versa. However, in an electrolytic cell this is reversed and a battery is needed to make the electrons flow.
(For both, e-'s flow through the wire, while ions flow through the electrolyte solution)