Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry > Higher Chemistry Unit 3- equilibria and redox > Flashcards

Higher Chemistry Unit 3- equilibria and redox Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

what are the rates like at equilibrium

A

the rates are equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are concentrations like at equilibrium

A

the concentrations are constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the symbol used to show a reversible reaction

A

arrow going forward and backward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

in what types of reactions can equilibrium form

A

reactions in which the reversible reaction occurs spontaneously.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is equilibrium

A

where the reaction continues to go backwards and forwards at the same rate and so the concentration of reactants and products appear to remain constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does a graph of concentration and time look like for a reaction approaching equilibrium

A

the concentration of the reactants decreases and the concentration of the products increases. when they reach equilibrium the lines become horizontal lines and so the concentration is constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a graph of rate and time look like for a reaction approaching eqm

A

the forward rate decreases and the reverse rate increases. when the graph reaches eqm the two lines co-inside and the rates become constant and equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does eqm lies to the left mean

A

when the concentration of reactants is greater tan the concentration of products.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what dos eqm lies to the right mean

A

when the concentration of products is greater than the concentration of the reactants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does a graph of eqm lies to the left look like

A

the concentration of reactants levels out higher than that of the products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does a graph of eqm lies to the right look like

A

the concentration of reactants is initially higher but it decreases as the concentration of the products increases and when eqm is achieved the concentration of products is higher. (looks like a fish)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the basic eqm equation

A

A + B <=> C + D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

does the reaction stop when eqm is achieved

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

does eqm consist 50% reactants and 50% products?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is le Chatelier’s principle

A

if a system at equilibrium is subjected to a change, the system will adjust to oppose the effect of the change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why is the position of the equilibrium changed in industry

A

to gain a higher yield or to increase the rate of reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where does the eqm move towards when you decrease the concentration

A

eqm moves towards the thing you’re removing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

where does the eqm move toward when you increase the concentration

A

eqm moves away from the thing you’re changing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what happens to eqm when you increase the concentration of A + B

A

you speed up the forward reaction. the eqm position moves to the right to counteract this change (more C and D are produced)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens to eqm when you decrease the concentration of C + D

A

you slow down the backward reaction. this means the eqm will move to the right in order to counteract the changes (more C and D are produced)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens to eqm when you increase the concentration of C and D

A

it will speed up the backwards reaction. the eqm therefore moves to the left to counteract this change (more A + B) are produced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what factors affect the position of eqm

A

concentration; temperature; pressure; catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what happens to eqm when you increase the temperature

A
  • the reaction attempts to decrease it
  • endothermic reaction is favoured
  • eqm moves in the reaction of the endothermic reaction (I.e. left)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens to eqm when you decrease the temperature

A
  • reaction attempts to increase it
  • exothermic reaction is favoured
  • eqm moves in direction of exothermic reaction (i.e. right)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how do you remove a H+ from an equation

A

add an OH- (H20)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how do you remove an OH- from an equation

A

add an H+ (H20)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how do you remove a silver ion from an equation

A

add a halide ion - e.g. CL^- add AgNO3 (formed precipitate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how do you remove a halide ion from an equation

A

add a silver ion - e.g. Ag^+ add NaCl to form precipitate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how do you remove Ba2+

A

add a SO4^2- compound- e.g. Ba2+ + Na2SO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

how do you remove SO4^2-

A

add a Ba^2+ compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what affect does removing a chemical from an equation have on the position of the eqm

A

it will affect the concentrations - eqm move from there

32
Q

if the forward reaction is exothermic the reverse reaction will be…

A

endothermic (and vice versa)

33
Q

in which state does changing the pressure affect the position of the eqm

A

only gases- ignore others

34
Q

what happens to eqm when you increase the pressure

A
  • eqm attempts to decrease it

- moves to the smaller moles (total moles of each side)

35
Q

what happens to eqm when you decrease the pressure

A
  • eqm attempts to increase it

- moves to larger moles (total moles of each side

36
Q

what happens to the forward and backward rates if a catalyst is added

A

the rates of both the forward and backward reactions will be increased by the same amount

37
Q

how does a catalyst affect the position of the eqm

A

it does not alter the position of equilibrium

38
Q

which bit of eqm does a catalyst affect

A

although it does not increase the percentage conversion of reactants into products it does speed up the rate of attainment of equilibrium

39
Q

what does the haber process make

A

ammonia

40
Q

what does the Ostwald process make

A

nitric acid

41
Q

what does the Contact process make

A

sulphuric acid

42
Q

what are the feedstocks of the Haber process

A

hydrogen and nitrogen

43
Q

what are the feedstocks of the Ostwald process

A

Ammonia, oxygen and water

44
Q

what are the feedstocks of the Contact process

A

sulphur and oxygen

45
Q

what are the ideal conditions for the Haber process

A
  • 450*C
  • iron catalyst
  • 200 atmospheres
46
Q

what are the ideal conditions for the Ostwald process

A
  • 800*C
  • platimun catalyst
  • 4-10 atmospheres
47
Q

what are the ideal conditions for the Contact process

A
  • 400-450*C
  • V205 catalyst
  • 1-2 atmospheres
48
Q

what happens to the position of the eqm if you add a reactant or remove a product

A

eqm moves to right (forward reaction)

49
Q

what happens to the position of eqm if you add a product or remove a reactant

A

eqm moves to the left (backwards reaction)

50
Q

what does acid have in it which could be important in influencing the position of the eqm

A

H+ and OH-

51
Q

what is oxidation

A

the loss of electrons

52
Q

what is reduction

A

gain of electrons

53
Q

how do you remember oxidation and reduction

A

OILRIG

54
Q

what is the reducing agent

A

causes reduction, it is oxidised, loss of electrons

55
Q

what is the oxidising agent

A

causes oxidation, it is reduced, gains electrons

56
Q

what is a redox equation

A

a reaction involving both oxidation and reduction

57
Q

in an exam how will you recognise a redox equation

A

it has the element on one side; and the ion of the element on the other side

58
Q

how do you write a redox equation

A
  1. write down ion electron equation for both
  2. balance so the electrons are equal
  3. add together omitting electrons
59
Q

what does an element need to be a good reducing agent

A

have a low ionisation energy as they need to be good at donating electrons to other substances

60
Q

what does an element need to be a good oxidising agent

A

high electronegativity as they need to be good at accepting electrons from other substances

61
Q

how do you figure out which ions are reacting in a redox equation

A
  1. draw a box (like the page in the data booklet)
  2. put all the ions in their position in the table
  3. the arrows MUST move anti clockwise (C shape).
  4. there should only be one option. if there is multiple it is the ones that are the furthest away.
62
Q

how do you recognise an oxidation equation

A

it loses electrons ( electrons are on right side of equation

63
Q

how do you recognise a reduction equation

A

it gains electrons (electrons are on the left side of the equation

64
Q

what way do you figure out which way to write the ion electron equation

A

move in a C shape. (Anticlockwise)

65
Q

what is the electrochemical series

A

it lists substances I order of how well they act as reducing/oxidising agents

66
Q

what is the reactivity like of the halogens

A

-as you go down group 7, the reactivity decreases (the lower down they are in the electrochemical series the more reactive they are)

67
Q

what is needed for a redox reaction to occur

A

the oxidising agent must be below the reducing agent

the OIL is below the RIG

68
Q

what can oxidising agents be used for

A

in the breakdown of colour compounds or to kill fungi

69
Q

what oxidising agent can break down coloured compounds

A

hydrogen peroxide- bleach, breakdown of coloured compounds; bleach wool, cotton, paper and lighten hair and teeth.

70
Q

what oxidising agent can be used to kill fungi

A

potassium permanganate - antiseptic, used to treat mild skin condition + fungal infections of the hands and feet.

71
Q

how do you figure out an ion electron equation

A
  1. check the main atoms are balanced
  2. check the oxygens are balanced- add water if they are not
  3. check the hydrogens are balanced- at H+ if not
  4. check the charges are balanced. - add electrons if not
72
Q

how do you recognise an oxidising/reducing agent in a redox equation

A

reducing agent- one being oxidised (losing e)

oxidising agent- one being reduced (gaining e)

73
Q

what group has the strongest reducing agents

A

group 1

74
Q

what group has the strongest oxidising agents

A

group 7

75
Q

give an example of a strong oxidising agent

A

hydrogen peroxide

76
Q

name an example of a gas that can be used as a reducing agent

A

carbon dioxide

Chemistry (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions