Brainscape's Knowledge GenomeTM

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


See full index

Poppy > Analysis And Synthesis > Flashcards

Analysis And Synthesis Flashcards

1
Q

What flame colour do lithium ions give

A

Crimson red

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

What flame colour do sodium ions give

A

Yellow

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

What flame colour do potassium ions give

A

Lilac

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

What flame colour do calcium ions give

A

Red

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

What flame colour do barium ions give

A

Green

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

Give the lithium and calcium give the same flame test colours how can we distinguish between them

A

With sodium hydroxide solution will show which is which because calcium ions will form a white precipitate but lithium will not

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

Which hydroxides are mostly insoluble in water

A

Ones with ions of 2+ and 3+ charges

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

What happens when sodium hydroxide is added to a solution of insoluble ions

A

A precipitate of a metal hydroxide is formed

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

Which 3 metals form white precipitate

A

Aluminium, calcium, magnesium

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

What happens to the aluminium hydroxide precipitate when excess sodium hydroxide solution is added

A

The precipitate of aluminium hydroxide dissolves

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

What colour is calcium hydroxide

A

Blue

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

What colour is iron (II) hydroxide

A

Green

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

What colour is iron (III) hydroxide

A

Brown

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

What can we use to show the reactions of positive ions with sodium hydroxide solution

A

Balanced ionic equations

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

What are the 3 test for negative ions

A

Carbonate ions
Halide ions
Surfate ions

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

Describe the test for carbonates (negative ion test)

A

Add dilute HCL to the substance to see if it fizzes. If it does and the gas produces turns limewater cloudy, the substance contains carbonate ions

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

Describe the test for halide ions (negative ions)

A

Add dilute nitric acid and then silver nitrate solution different negative ions form different coloured precipitates

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

In the test for negative halide ions what colour precipitate do chloride ions form

A

A white precipitate

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

In the test for negative halide ions what colour precipitate do bromide ions form

A

A cream coloured precipitate

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

In the test for negative halide ions what colour precipitate do iodide ions form

A

A yellow precipitate

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

Describe the test for surface ions (negative ions)

A

Add dilute hydrochloride acid and then barium chloride solution. If a white precipitate forms, sulfate ions are present

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

Why must nitric acid be added and not HCL or sulphuric acid when testing with silver nitrate solution for halides?

A

HCL contains chloride ions and sulphuric acid contains sulfate ions which both give precipitates with silver nitrate solution

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

How can positive ions be identified

A

Using a flame test

Using sodium hydroxide solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is titration

A

A method for measuring the volumes of 2 solutions that react together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is used to measure accurately the volume of alkali put into a conical flask

A

A pipettes

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

What is added to the alkali which is in the conical flask

A

Indicator

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

What is used to gradually add the acid to the alkali in a titration experiment

A

A burette

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

What is the difference between a pipette and a burette

A

A pipette measures a fixed, has a single graduation, and has no tap; a burette measures different volumes, has graduations, has a tap

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

When is the end point of titration reached

A

The indicator changes colour

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

How is repeatability of the titration experiment improved

A

The titration should be done several times

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

What can concentration be measured in

A

Grams per decimetre cubed (g/dm3)

Moles per decimetre cubed (mol/dm3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What do we need to calculate concentration

A

The mass or the number of moles dissolved in a given volume of solution

33
Q

What can be used to calculate mass or number of moles of a substance in any volume of solution

A

The volume of a solution and its concentration

34
Q

How do you calculate the concentration of a solution in g/dm3

A

1) to calculate what 1cm3 of the solution contains divide the value of the NAMED solution (in grams) by the value of the unnamed solution (in cm3)
2) to calculate what 1dm3 contains, times the answer to the previous step by 1000

35
Q

How do you calculate the concentration of a solution in mol/dm3

A

1) calculate the value of 1 mole of the named solution (relative formula mass)
2) divide the previously worked out concentration of the solution in g/dm3 by the relative formula mass of the the named solution

36
Q

What are the steps to calculate the mass of a solution (with the concentration stated) which is dissolves in another solution

A

1) to calculate what 100cm3 contains, 100 x the concentration value/1000
2) calculate the relative formula mass of the solution
3) times the relative formula mass by the previous worked out answer

37
Q

What is needed so the concentration of solution be calculated in a titration experiment

A

If the concentration of one of the solutions is known and the volumes that react together are known

38
Q

How are the concentrations calculated in titration

A

Using balanced symbol equations and moles

39
Q

What are the steps in calculating an unknown concentration in a titration calculation

A

1) write the balanced equation
2) understand that the given concentration (eg. 0.5) means the value given in divided by 1000 0.5/1000
3) times the volume of the acid/ solution with a given concentration by the concentration value (0.5/1000)
4) from the equation work out how many moles of the unknown substance will react with what value of the Unknown (concentration) solution eg 0.010 mol of HCL will react with 0.010 mol of sodium hydroxide
5) so the concentration is the value calculated from step 5 divided by the stated volume of the Unknown (concentration) solution x 100

40
Q

What purposes may chemists analyse substances for

A

Environmental, medical, forensic investigations

41
Q

What are qualitative tests

A

Tests which simply find out if a substance is in a sample, such as testing the ions

42
Q

What can titration so tells you

A

How much of a substance is in a sample

43
Q

What are examples of quantitative methods

A

Mass spectrometry and gas chromatography

44
Q

When is it necessary to use quantitative analysis

A

When we need to know the quantity of a substance in a sample

45
Q

What can a large data base build up

A

help identify substances in samples, individuals or to monitor changes in amounts of substances over time

46
Q

Why is it important to have a large database for DNA analysis to identify individuals

A

Because everyone’s DNA is different

47
Q

When is equilibrium reached for a reversible reaction in a closed system

A

When the rate of the forward reaction is equal to the rate of the reverse reaction

48
Q

What happens in equilibrium

A

Both reactions continue to happen but the amounts of reactants remain constant

49
Q

How can the amounts of the reactants and products for a reversible reaction be changed

A

By changing the reaction conditions

50
Q

How will increasing the concentration of the reactant name the amount of product produced

A

It will cause more product to be formed as the system tries to achieve equilibrium

51
Q

What happens if a product is removed in a equilibrium reaction

A

More reactants will react to try to achieve equilibrium and so more product is formed

52
Q

To make SO3, the reaction 2SO2 + O2 2SO3 is done in a reactor over a heated catalyst. Why is the SO3 removed from the reactor as soon as it is made

A

So more of the reactants react and more SO3 is produced

53
Q

What happens if the conditions of a system change at equilibrium

A

The position of equilibrium changes as if to try to cancel out the change

54
Q

How does increasing the pressure favour the equilibrium

A

UIf the pressure is increased the equilibrium will shift to try to reduce the pressure favouring the reaction that produces fewer molcules of gas

55
Q

If the forward reaction produces more Molecules of gas…..

A

An increase in pressure decreases the amount of products formed
A decrease in pressure reduces the amount of products formed

56
Q

If the forward reaction produces fewer molecules of gas

A

An increase in pressure increases the amount of products formed
A decrease in pressure decreases the amounts of products formed

57
Q

Increasing the pressure …….. The amount in the mixture at equilibrium

A

Increases

58
Q

Reversible reaction are ……. In one direction and …… In the other

A

Exothermic

Endothermic

59
Q

Increasing the temperature favours which reaction

A

The endothermic reaction, the equilibrium shifts as it to lower the temperature by taking in energy

60
Q

Decreasing the temperature favours which reaction

A

Exothermic reaction

61
Q

If the forward reaction is exothermic…

A

An increase in temperature decreases the amount of products formed
A decrease in temperature increases the amount of products formed

62
Q

If the forward reaction is endothermic….

A

An increase in temperature increases the amount of products formed
A decrease in temperature decreases the amount of product formed

63
Q

What is the habet process used to make

A

Ammonia

64
Q

What is ammonia used as

A

Fertilisers, other chemical s

65
Q

Where is hydrogen and nitrogen obtained from

A

Natural gas

66
Q

How is nitrogen and hydrogen from the air turned into ammonia

A

They are purified and mixed in the correct proportions

67
Q

What are the conditions for the habet process

A

Iron catalyst
450 degrees
200 atmospheres, pressure

68
Q

Why are those conditions for the haber process chosen

A

They give a fast rate of reaction

Reasonable yield of ammonia

69
Q

What is the balanced symbol equation for the haber process

A

N2 + 3H2 2NH3

70
Q

The haber process is ………..

A

Reversible

71
Q

What is the yield of the haber process and why is this

A

15% as some of the ammonia breaks down into nitrogen and hydrogen

72
Q

How is the ammonia obtained at the end of the haber process

A

The gases are cooled so the ammonia condenses

The liquid ammonia is separated from the unreacted gases

73
Q

What is done in the haber process to conserve raw materials

A

The unreacted gases are recycled and not wasted

74
Q

Why does increasing the pressure increase the yield of ammonia

A

The products have fewer molecules of gas than the reactants so the higher the pressure the greater the yield

75
Q

What is bad about the higher pressure needed for the haber process

A

More energy is needed to compress the gas
Stronger reaction vessels and pipes are needed
Which all increase the cost

76
Q

Why is a pressure of 200 atmospheres used in the haber process

A

It is a compromise between the cost and yield

77
Q

What type of reaction if the forward reaction in the haber process

A

Exothermic

78
Q

Because the forward reaction of the haber process Is exothermic what type of temperature will increase the yield of ammonia

A

A lower temperature

79
Q

Why is a temperature of 450 degrees used for the haber process

A

A lower temperature, although it would increase the yield, the reaction rate decrease as the temperature is lowered and the iron catalyst becomes ineffective so it would take longer to produce ammonia

Poppy (12 decks)

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