chapter 6: equilibrium Flashcards

1
Q

what is the equilibrium constant

A

K
K = [prod]/[react]

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2
Q

what does it mean if K >1, K<1

A

the reaction is product favored, reactant favored

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3
Q

do equilibrium constants have dimensions

A

no, they are dimensionless

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4
Q

in the equation aA+bB = cC+ dD what happens if A is a soute and when D is a gas

A
  • A is a solute, [A] = 1/M
    M = moles of solute /Liters
  • D is a gas, means that the pressure of D in bars/ 1 bar and written as Pd
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5
Q

what state is each quantitiy in the ratio given

A

at standard state

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6
Q

what are the different standard states

A
  1. conc. of solutes = mol/ L
  2. conc. of gases = bars
  3. do not include solids,liquids, and solvents because they are unity
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7
Q

what are some ways to manipulate the equilibrium constant

A
  1. reaction is reverse = 1/K
  2. two reactions are added together = multiply them together to get the new K
  3. if n reaction is added then K is the product of the n individual equilibrium constants
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8
Q

what is enthalpy

A

heat absorbed or released

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9
Q

what is entropy

A

the dispersal of energy into molecular motions, random

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10
Q

what is the enthalpy change

A

heat absorbed or released

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11
Q

what is the standard enthalpy change

A

heat absorbed when all reactants and products are in their standard states

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12
Q

if it is delta H is negative

A

exothermic

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13
Q

delta H is positive

A

endothermic

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14
Q

what is the symbol for entropy

A

delta S

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15
Q

what is the equation for entrop

A

S = qrev( heat abosrbed) / Temperature (kelvin)

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16
Q

what does a positive q mean what does a negative q mean

A
  1. heat is absorbed
  2. heat is removed
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17
Q

what states have higher entropy than the other

A

gas> liquid> solid

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18
Q

if S is positive, if S is negative

A
  1. greater entropy than reactants
  2. lower entropy than the reactants
19
Q

which has more entropy, ions or solid salt

20
Q

what pushes a chemical reaction in the forward reaction

A
  1. H is (-)
  2. S is (+)
    or both,
    reaction is disfavored in the reverse reaction
21
Q

what will decide whether the reaction will be favored if both H and S are positive

A

the gibbs free energy

22
Q

What is the equation for gibbs free energy

A

G = change in H - T(change in S)

23
Q

what sign is G if it is favored

24
Q

if G is negative what does it tell us about H and T

A

H has greater favorable influence than S because so it means that H is more negative

25
what is the equation for K using Gibbs
K = e^(change in G)/ RT
26
if K is greater than 1 what does it tell us about G
that G is negative because it is product favored reaction
27
what does a large K tell us
that something is very soluble in water
28
if K is greater than 1 is the reaction spontaneous
yes it is and it is not spontaneous when K is less than 1( because G is positive)
29
what is the Le chatelier's principle
the direction in which the system proceeds to move back to equilibrium
30
1. qk 3.q=k
1. reactant favored 2. product favored 3. at equilibrium
31
what is the difference between thermodynamics and kinetics
1. thermodynamics tells us the direction of the equation and kinetics tells us how fast it is going
32
what is the Ksp
equilibrium constant that gives us more information on how soluble a salt can be
33
what is a saturated solution
equilibrium with excess and undissolved solid
34
what happens if there is an aqeuous solution that is still left in contact with the excess solid
the solid will dissolve until the Ksp is satisfied
35
what is a mercurous ion Hg+
dimer that consists of two identical units bound together
36
what is disproportionation
the process in which an element in an intermediate oxidation state, gives products in both the higher and lower oxidation states
37
what reactions does solubility not account for
1. hydrolysis 2. disproportionation 3. ion pairing
38
what is the common ion effect
salt is LESS soluble if one of its constituent ions is already present in the solution.
39
what does a small ksp indicate
that the reaction is less soluble
40
what is a complex ion
anion that precipitate metals are observed to form complex ions
41
what is a ligand
any atom or group of atoms attached to species of interest
42
what is an example of a ligand attached to a complex ion
1. PbI+, PbI3 and PbI - I is the ligand - Pb is a lewis acid and I is a lewis Base
43
if anion X- precipitates metal M+, what is observed
high concentration of X- causes solid MX to redissolve - increased solubility arises from the formation of complex ions like MX-2