Mcat - Inorganic Chemistry

Front 1

What was Planck'squantum theory?

Back 1

Energy emitted as electromagnetic radiation from atter comes in discrete bundles called quanta; E = hf

Front 2

What is Planck's constant (h) equal to?

Back 2

6.63 × 10^-34 J•s

Front 3

What is the velocity of light (c)?

Back 3

3.00 × 10^8 m/s

Front 4

What are the Balmer and Lyman series?

Back 4

- Balmer is group of hydrogen emission lines corresponding to transitions above n = 2 down to n = 2 (4 wavelengths in visible region)
- Lyman series is a group of hydrogen emission lines that correspond to transition from levels above n = 1 down to n = 1 (higher transitions occur in the UV region)

Front 5

Do the wavelengths of absorption spectrum correspond directly to the wavelengths of emission spectrum?

Back 5

Yes

Front 6

What was Bohr's assumption?

Back 6

Electrons follow a circular orbit at a fixed distance from the nucleus; no longer considered valid

Front 7

What is Pauli's exclusion principle?

Back 7

No two electrons in a given atom can possess the same set of four quantum numbers

Front 8

What is Hund's rule?

Back 8

Within a given subshell, orbitals are filed such that there are a maximum number of half-filled orbitals with parallel spins

Front 9

What are paramagnetic and diamagnetic materials?

Back 9

Paramagnetic have unpaired electrons, so a magnetic field aligns the spins of these electrons and weakly attracts the atoms; diamagnetic materials have no unpaired electrons and are slightly repelled by a magnetic field

Front 10

What are the valence electrons for the groups I-VIIIA and the transition elements?

Back 10

- Groups I and IIA: outermost s electrons
- Groups III-VIIIA: outermost s and p electrons
- Transition elements: Outermost s subshell and d subshell of next-to-outermost energy shell

Front 11

What is atomic radius equal to?

Back 11

One-half the distance between the centers of two atoms of that element that are just touching each other

Front 12

What is electron affinity?

Back 12

Energy change that occurs when an electron is added to a gaseous atom; represents the ease with which the atom can accept and electron

Front 13

What elements can expand their octets to include more than eight electrons?

Back 13

Those beyond the second roy, by incorporating d orbitals

Front 14

What is a coordinate covalent bond?

Back 14

Shared electron pair comes form the lone pair of one of the atoms in the molecule; once such a bond forms, it is indistinguishable from any other covalent bond; typically found in Lewis acid-base compounds

Front 15

What is a Lewis acid?

Back 15

Compound that can accept an electron pair to form a covalent bond

Front 16

What geometric arrangement do molecules take on when there are 3, 4, 5, and 6 regions f electron density around the central atom?

Back 16

3: trigonal planar (120°)
4: tetrahedral (109°)
5: trigonal bipyramidal
6: octahedral

Front 17

How do orbitals overlap in σ and π bonds?

Back 17

σ: head-to-head
π: parallel

Front 18

What are London dispersion forces?

Back 18

At any particular point in time, electrons shared in a covalent bond are located randomly throughout the orbital, causing random short-lived dipoles

Front 19

What is a metathesis reaction?

Back 19

Another name for a double displacement reaction; occurs when both start out as aqueous and one is removed from the solution as a precipitate, gas, or weak electrolyte

Front 20

What is the first step in determining the limiting reagent?

Back 20

Determine the number of moles in each

Front 21

Describe how the rate law equation is determined.

Back 21

r = k [A]^x [B]^y

Must be determined experimentally; given three trials; plug two with the same [A] in and divide to determine x; plus two with the same [B] in and divide to determine y; plus values in to determine k

Front 22

What is the order of the reaction equal to?

Back 22

x+y from r = k [A]^x [B]^y

Front 23

What is the half life of a first order reaction?

Back 23

ln2/k = 0.693/k

Front 24

What is the equation for the concentration of a substance from a first order reaction at any time?

Back 24

[At] = [Ao] e^-kt

Front 25

What is the reaction rate according to collision theory?

Back 25

rate = Zf, where Z is the total number of collisions per second and f is the fraction of collisions that are effective

Front 26

When are the orders in a reaction equation equal to the stoichiometric numbers?

Back 26

When the reaction occurs in a single step

Front 27

What is the Law of Mass Action?

Back 27

For aA + bB --- cC + dD,

kc = [C]^c [D]^d / [A]^a [B]^b

Front 28

What is an adiabatic process?

Back 28

No heat exchange occurs

Front 29

What is the formula for heat gain/loss in termsof calorimetry?

Back 29

q = mc∆T

Front 30

Is ∆H positive or negative when energy is released?

Back 30

Negative

Front 31

What is the formula for Gibbs Free Energy?

Back 31

∆G = ∆H - T∆S

Front 32

What does it mean if ∆G is negative?

Back 32

The reaction is spontaneous

Front 33

What does it mean if ∆S is negative?

Back 33

Becomes more ordered

Front 34

What are the conditions for standard free energy (∆G°)?

Back 34

25°C; 1 atm; 1 M

Front 35

What is the equation for standard free energy in terms of the equilibrium constant?

Back 35

∆G° = -RT lnKeq

Front 36

What is the equation giving the relationship between ∆G and ∆G°?

Back 36

∆G = ∆G° + RT lnQ

Q = Kc = [C]^c [D]^d / [A]^a [B]^b

Front 37

Describe the graph for pressure vs. volume of a gas.

Back 37

Downward curve

Front 38

Describe the graph for volume vs. temperature of a gase.

Back 38

Direct upward line

Front 39

What is Avogadro's principle?

Back 39

n1/V1 = n2/V2

Front 40

What units should temperature be in when working with gases?

Back 40

K

Front 41

How do you determine the density of gas at a new P and T?

Back 41

V2 = V1P1/T1 (T2/P2)

Divide grams/mole by V2 to get density

Front 42

What are the 5 assumptions of the kinetic molecular theory?

Back 42

1. Gases made up of particles with negligible volume
2. Gas atoms exhibit no intermolecular attractions/repulsions
3. Gas particles are in continuous, random motion
4. Collisions between gase particles are elastic
5. Average kinetic energy of gas particles is proportional to absolute temperature

Front 43

What is the equation for the rate of effusion?

Back 43

r1/r2 = (MM2/MM1)^0.5

MM = molecular weight

Front 44

What is the critical point?

Back 44

Temperature at which no distinction between liquid and gas is possible

Front 45

What are four colligative property effects?

Back 45

Derived solely from the number of particles present
1. Freezing-point depression
2. Boiling-point elevation
3. Osmotic pressure
4. Vapor-pressure lowering

Front 46

What is the equation for the freezing-point depression?

Back 46

∆Tf = kf m

m = molarity

Front 47

What is the equation for the boiling-point elevation?

Back 47

∆Tb = kb m

m = molarity

Front 48

Describe osmotic pressure.

Back 48

In two compartments (one with higher solute concentration) connected by a membrane that the solute cannot pass through, water level will rise in salt until its pressure counteract influx of further water

π = mRT

m = molarity
R = ideal gas constant
T = temperature in K

Front 49

When solute B is added to solvent A, what is the formula for vapor-pressure lowering?

Back 49

∆P = Xb/P°a

Xb = mole fraction of solute B in solvent A

Front 50

What are the 7 rules of salt solubility?

Back 50

1. Salts of alkali metals are water soluble
2. Salts of ammonium ion (NH4+) are water soluble
3. Chlorides, bromides, and iodides are water soluble, except Ag+, Pb2+, and Hg2^2+
4. Slats of sulfate ion (SO4^2-) are water soluble, except alkali metals and Ca2+, Sr2+, Ba2+, and Pb2+
5. Metal oxides are insoluble, except alkali metals and CaO, SrO, and BaO, which hydrolize to form corresponding metal hydroxides
6. Hydroxides are insoluble except alkali metals ad Ca2+, Sr2+, and Ba2+
7. Carbonates (CO3^2-), phosphates (PO4^3-), sulfides (S^2-), and sulfites (SO3^2-) are insoluble, except alkali metals and ammonium

(Any nitrate (NO3^-), chlorates (ClO3^-), and acetate (C2H3O2^-) is soluble)

Front 51

In nomenclature, what is the difference between -ic and -ous?

Back 51

-ous denotes the lesser charge
-ic denotes the greater charge

Front 52

Given the nomenclature for oxyanions as they contain more oxygen.

Back 52

Hypo-ite
ite
ate
Per-ate

Front 53

What does bi- represent in bicarbonate?

Back 53

The addition of a single H

(The addition of two H would be called dihydrogen)

Front 54

What is molality?

Back 54

moles of solute per kilogram of solvent

Front 55

What is normality?

Back 55

number of ram equivalent weights of solute per liter of solution

Front 56

How do you determine the volume of a certain M solution that must be used to create a given volume of a given M solution?

Back 56

M1V1 = M2V2

Front 57

What is the formula for Ksp?

Back 57

Ksp = [A^n+]^m [B^m-]^n

(Same equation for Ksp)

Front 58

How do you determine if precipitation will occur?

Back 58

If Qsp (same equation for Ksp but not at equilibrium) > Ksp, solution is supersaturated and precipitation will occur
If Qsp = Ksp, solution is saturated at equilibrium

Front 59

What are Arrhenius, Bronted-Lowry, and Lewis acids?

Back 59

Arrhenius: produces H+
Bronsted-Lowry: produce protons
Lewis: electron-pair acceptor (donating protons is like accepting electrons)

Front 60

Describe the nomenclature of acids of oxyanions with increasing oxygens?

Back 60

Hypo-ous
-ous
-ic
Hyper-ic

Front 61

What is the water dissociation constant equal to?

Back 61

[H+][OH-] = 10^-14

pH + pOH = 14

Front 62

How is a 1 × 10^-8 solution of HCl acidic?

Back 62

The contribution of OH- and H+ from water can only be neglected if the concentration of the acid or base is greater than 10^-7; have to use kw = 10^-14 = (x + 1 × 10^-8)(x); in this case, x = 1.05 × 10-7 and pH = 6.98, which is slightly acidic

Front 63

What is the negative log of n × 10^-m?

Thus, if Kb = 1.0 × 10^-7, what is pKb equal to?

Back 63

m - log n

7
(-log of 10^-7)

Front 64

What is the acid dissociation constant?

Back 64

Ka = Kc = [H30+][A-]/[HA]

Front 65

Is H20 usually produced in when an acid reacts with a strong base?

Back 65

No, because hydroxides are not usually strong bases

Front 66

When a base reacts with a strong acid, why is the solution acidic?

Back 66

Because when the salt turns back into a base, is leaves H3O+ behind after it takes the OH- from H2O

Front 67

Describe the titration curve for a weak acid titrated with a strong base compared to that of a strong acid titrated with a strong base.

Back 67

The weak acid titration will rise in pH a little bit more rapidly to the equivalent point, whereas the strong acid is mostly flat until it hits the equivalent point

Front 68

What does a buffer consist of?

Back 68

Weak acid/base and a salt (which consists of the respective conjugate base/acid and a cation)

Front 69

What is the Henderson-Hasselbalch equation?

Back 69

Used to estimate the pH of a solution in the buffer region

pH = pKa + log [conjugate base]/[weak acid]

pOH = pKb + log [conjugate acid]/[weak base]

Front 70

Give the order of electronegativity for F, Cl, and O

Back 70

F > O > Cl

Front 71

Do spontaneous or nonspontaneous reactions occur in galvanic and electrolytic cells?

Back 71

Galvanic: spontaneous
Electrolytic: non-spontaneous

Front 72

What are the electrodes called at which oxidation and reduction occur?

Back 72

Anode: oxidation
Cathode: Reduction

Front 73

Describe a Daniell cell.

Back 73

Type of galvanic cell (voltaic cell)

Zn in anode cell and Cu2+ in cathode cell; both in SO4^2- solutions
Zn oxidizes to Zn 2+; electrons flow through salt bridge to cathode, where Cu2+ is reduced to Cu causing the cathode to build up

Front 74

Is the anode in an electrolytic cell positive or negative?

Back 74

Positive, because it is attached to the positive part of the battery, so it sucks up electrons, causing negative chlorine to gravitate towards it

Front 75

What does a more positive reduction potential (E°) indicate?

Back 75

More likely to be reduced

Front 76

What is EMF?

Back 76

Standard electromotive force = sum of reduction potentials

Front 77

What is ∆G equal to in terms of EMF?

Back 77

∆G -= -n F EMF = -RT lnKeq

n = # of electrons exchanged
F = Faraday's constant

Front 78

What is the Nerst equation?

Back 78

EMF = EMF° - (RT/nF) (lnQ)

Used to determine the equilibrium reduction potential of a half-cell in an electrochemical cell.

Front 79

Describe the valence electrons of Se?

Back 79

6: 2 in 4S and 4 in 4P (don't count 3D)

Front 80

Describe the valence electrons of S in sulfate?

Back 80

Bonded to four oxygens (8 valence electrons); two of the oxygens are double-bonded (4 more valence electrons); total of 12 valence electrons

6 fill 3s and 3p; 6 others enter 3d

Front 81

How do you decide what the most stable resonance structure is?

Back 81

The negative charge should be on the most electronegative atom

Front 82

Do nonbonding electron pairs factor into the geometry?

Back 82

Yes, so NH3 is tetrahedral

Front 83

When working with gases, what unit do you have to work with?

Back 83

atm

Front 84

How do you convert from mm Hg to atm?

Back 84

divide by 760

Front 85

How many liters does a mole of gas occupy?

Back 85

22.4 L

Front 86

What is the difference between molarity, molality, and normality?

Back 86

Molarity = moles/liter solution
Molality = moles/kg solvent
Normality = kg/liter solution (1 molar sulfuric acid = 2 normal for acid-base rxns, because each mole of sulfuric acid provides 2 moles of H+

Front 87

How do you find ksp?

Back 87

1. Determine how the molecule separates in solution
Ex: Fe(OH)3 ---- Fe3+ + 3OH-

2. Ksp = the products to the power of their coefficients
Ex: ksp = [Fe3+] [3OH-]^3

4. Replace molecules with x
Ex: ksp = [x] [3x]^3

5. Replace x with solubility

Front 88

What are the three atoms that are electronegative enough to induce hydrogen bonding?

Back 88

F, O, and N (all more electronegative than Cl)

F>N>O>Cl

Front 89

Is the conjugate base of a weak acid a strong base or a weak base?

Back 89

A strong base (the weak acid doesn't want to release the H, so the conjugate base wants to reclaim the H); just like the conjugate base of a strong acid is weak

Front 90

What is Ka equal to?

Back 90

Ka = [H][A]/[HA]

Front 91

What is the formula for sulfuric acid? Is it a strong acid?

Back 91

H2SO4; yes, it is a very strong acid

Front 92

Why does a higher pH mean the solution is more basic?

Back 92

pH = -log [H] = log 1/ [H] ~ decreased [H] increases pH

Front 93

When a bond is formed, is energy gained or released?

Back 93

Released ~ delta H is negative

Front 94

Give the equation for: carbonate, sulfate, phosphate, nitrate, acetate, chlorate, chromate

Back 94

Acetate: C2H3O2^-
Chlorate: ClO3^-
Nitrate: NO3^-
Carbonate: CO3^2-
Sulfate: SO4^2-
Chromate: CrO4^2-
Phosphate: PO4^3-