Brainscape's Knowledge GenomeTM

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


See full index

CHEMISTRY Questions > C4 Chemical changes > Flashcards

C4 Chemical changes Flashcards

1
Q

What is the reactivity series?

A

A list of metals ordered by their reactivity

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

How can the order of reactivity for specific metals be found?

A

Add the metals to water or acid and see which ones react the most (by how much fizzing there is)

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

What is the name for a reaction where oxygen is added to form a compound?

A

Oxidation

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

What is the name for a reaction where oxygen is removed from a compound?

A

Reduction

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

Which is metal in the reactivity series is the first one that doesn’t react with acid?

A

Copper as it is less reactive than hydrogen

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

Explain why zinc can be extracted from zinc oxide with carbon but magnesium cannot be extracted from magnesium oxide with carbon

A

Magnesium is more reactive than carbon (1), Zinc is less reactive than carbon (1), Carbon can therefore remove oxygen from zinc oxide but not magnesium oxide (1)

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

Explain why gold and silver can be found pure in the Earth’s crust

A

They are very unreactive

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

What process is used to extract metals less reactive than carbon?

A

Reduction with carbon

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

Which metals are extracted by reduction with carbon?

A

Iron, Zinc and Copper

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

What process is used to extract metals more reactive than carbon?

A

Electrolysis

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

Define an ore

A

A rock containing enough metal in it for it to be economically worthwhile to extract the metal.

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

Define a displacement reaction

A

A reaction in which a more reactive element takes the place of a less reactive element

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

Define oxidation in terms of electrons

A

Oxidation is the loss of electrons

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

Define reduction in terms of electrons

A

Reduction is the gain of electrons

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

Which of the substances below has been oxidized and which has been reduced? Al³⁺ + Fe → Fe³⁺ + Al

A

Aluminium has been reduced and iron has been oxidised

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

Show two half equations for the reaction below: Al³⁺ + Fe → Fe³⁺ + Al

A

Al³⁺ + 3e⁻ → Al, Fe → Fe³⁺ + 3e-

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

Define acid in terms of pH

A

A substance with a pH of less than 7

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

Define acids in terms of ions

A

A substance which releases H⁺ ions in solution

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

What does (aq) stand for?

A

Aqueous: when something is dissolved in water. E.g. NaCl(aq) is salt water

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

State the three common acids and give their formulae

A

Hydrochloric acid, HCl(aq), Sulphuric acid, H₂SO₄(aq), Nitric acid, HNO₃

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

What is the formula of the carbonate ion?

A

CO3^2-

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

What is the formula of the sulphate ion?

A

SO4^2-

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

What is the formula of the nitrate ion?

A

NO3-

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

What is the fomula of the hydroxide ion?

A

OH-

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

What is a neutral solution?

A

A solution with a pH of 7. Water is an example.

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

How do you measure pH?

A

With an indicator or pH probe.

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

What is a base?

A

A metal oxide, hydroxide or carbonate that will react with an acid. E.g. copper oxide

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

What is an alkali?

A

A soluble base. E.g. sodium hydroxide

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

Which ions are always present in a solution of an alkali?

A

OH⁻

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

What is a salt?

A

An ionic compound formed during neutralisation

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

What type of salts are formed by the three main acids?

A

Hydrochloric acid produces chlorides, sulphuric acid = sulphates, nitric acid = nitrates

32
Q

What is a neutralisation reaction?

A

A reaction involving an acid that results in a neutral solution

33
Q

Which ions always react together in a neutralization reactions between acids and alkalis?

A

H⁺ and OH⁻

34
Q

Write the equation showing the reaction between H⁺ and OH⁻ ions

A

H⁺ + OH⁻ → H2O

35
Q

metal + acid →

A

→ salt + hydrogen gas

36
Q

metal hydroxide + acid →

A

→ salt + water

37
Q

metal oxide + acid →

A

→ salt + water

38
Q

metal carbonate + acid →

A

→ salt + water + carbon dioxide

39
Q

How do you make a pure salt from an acid?

A

React the acid with a excess base then filter off the excess base. E.g. to make copper sulphate react copper oxide with sulphuric acid

40
Q

If a salt is in solution, how do you extract it as a solid?

A

Allow the water to evaporate off and it will leave the salt behind as a solid.

41
Q

What is a strong acid?

A

An acid which completely ionises in water. E.g. when HCl is in water all the HCl molecules split up into H⁺ and Cl⁻

42
Q

What is a weak acid?

A

An acid which only partially ionises in water. E.g. in ethanoic acid only some of the molecules will have split up into the ethanoate ion and H⁺ ions.

43
Q

What is the relationship between the strength of an acid and its pH?

A

As an acid increases in strength the pH decreases.

44
Q

What is a concentrated acid?

A

An acid where there are lots of acid particles in the water.

45
Q

What is a dilute acid?

A

An acid where there are fewer acid particles in the water.

46
Q

What is pH a measure of?

A

pH is measure of concentration of H⁺ in a solution.

47
Q

If the pH increases by 1 what does this mean has happened to the H+ ion concentration?

A

It has decreased by a factor of 10

48
Q

How is a tritartion carried out?

A

An acid of known concentration is placed in a conical flask with a few drops of indicator. An alkali of unknown concentration is added in until there is a permanent colour change

49
Q

How can you make a titartion more accurate

A

Do a rough titration first, use a white tile to see the colour change better, add the alkali drop by drop near the end point and repeat it until you get consistent results.

50
Q

Which ions are in CaCO3

A

Ca2+ and CO32-

51
Q

Which ions are in Mg(OH)₂

A

Mg2+ and 2 ions of OH⁻

52
Q

What is the formula of iron (III) oxide?

A

Fe2O3

53
Q

What is the formula of sodium sulphate?

A

Na2SO4

54
Q

Is this process oxidation or reduction? Al → Al³⁺ + 3e⁻

A

Oxidation

55
Q

Is this process oxidation or reduction? Na⁺ + e⁻ → Na

A

Reduction

56
Q

What is electrolysis?

A

Using electricity to break down a substance

57
Q

What happens to an ionic substance when it is melted or dissolved in water?

A

The ions become free to move around

58
Q

What is an electrolyte?

A

A solution or liquid containing ions

59
Q

What is the name for the positive electrode?

A

The anode

60
Q

What is the name for the negative anode?

A

The cathode

61
Q

Which electrode do negative ions move to?

A

Cathode

62
Q

Which electrode do positive ions move to?

A

Anode

63
Q

Balance the equation: Al3+ + e⁻ → Al

A

Al3+ + 3e⁻ → Al

64
Q

Balance the equation: Cl⁻ → Cl2+ e⁻

A

2Cl⁻ → Cl2 + 2e⁻

65
Q

Balance the equation: O2- → O2 + e⁻

A

2O2- → O2 + 4e⁻

66
Q

What will be the products for the electrolysis of molten iron bromide?

A

Iron and bromine

67
Q

What will be the products for the electrolysis of molten zinc oxide?

A

Zinc and oxygen

68
Q

If electrolysis of a solution containing a metal more reactive than hydrogen is carried out what forms at the cathode?

A

Hydrogen

69
Q

If electrolysis of a solution containing sulphate, carbonate or nitrate ions what is produced at the anode?

A

Oxygen

70
Q

What is the main disadvantage of using electrolysis to extract metals?

A

Requires a large amount of energy to melt the compounds and to produce the necessary electricity

71
Q

Why is aluminium oxide mixed with cryolite when extracting aluminium?

A

To lower the melting point

72
Q

What is produced at the anode and cathode in the electrolysis of aluminium oxide?

A

Aluminium at the cathode and oxygen at the anode

73
Q

Why does the anode need to be replaced in the electrolysis of aluminium oxide?

A

The oxygen reacts with the carbon electrode to produce carbon dioxide.

74
Q

In the electrolysis of sodium chloride solution, what are the products?

A

Chlorine gas and hydrogen gas

75
Q

Why is sodium not produced in the electrolysis of sodium chloride solution?

A

It is more reactive than hydrogen so hydrogen is produced instead.

76
Q

In the electrolysis of lithium sulphate solution, what are the products?

A

Chlorine gas and oxygen gas

CHEMISTRY Questions (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions