Brainscape's Knowledge GenomeTM

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


See full index

iGCSE Chemistry > 3.4 Atmosphere & acids > Flashcards

3.4 Atmosphere & acids Flashcards

1
Q

What is pH < 7?

A

acidic

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

What is acidic?

A

pH < 7

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

What is pH = 7

A

neutral

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

What is neutral?

A

pH = 7

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

What is pH > 7?

A

alkaline

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

What is alkaline?

A

pH > 7

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

What is a strong acid?

A

0-3

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

What is the colour of a strong acid on the universal indiator?

A

red

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

What is a weak acid?

A

3-6

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

What is the colour of a weak acid on the universal indictaor?

A

orange 3-4
yellow 5-6

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

What is the colour of a neutral substance on the universal indicator?

A

green

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

What is a weak alkali?

A

8-10

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

What is the colour of a weak alkali on the universal indicator?

A

light blue

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

What is a strong alkali?

A

11-14

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

What is the colour of a strong alkali on the universal indicator?

A

dark blue 11-13
purple 14

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

What is the colour of an acid in methyl orange?

A

red

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

What is the colour of a neutral in methyl orange?

A

yellow

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

What is the colour of an alkali in methyl orange?

A

yellow

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

What is the colour of an acid in phenolphthalein?

A

colourless

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

What is the colour of a neutral in phenolphthalein?

A

colourless

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

What is the colour of an alkali in phenolphthalein?

A

pink

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

What is the colour of an acid using red litmus paper?

A

red

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

What is the colour of a neutral using red litmus paper?

A

red

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

What is the colour of an alkali using red litmus paper?

A

blue

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

What is the colour of an acid using blue litmus paper?

A

red

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

What is the colour of a neutral using blue litmus paper?

A

blue

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

What is the colour of an alkali using blue litmus paper?

A

blue

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

What is the approx % of nitrogen in the air?

A

78%

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

What is the approx % of oxygen in the air?

A

21%

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

What is the approx % of argon in the air?

A

0.96%

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

What is the approx % of carbon dioxide in the air?

A

0.04%

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

What is the formula for working out the composition of air?

A

final - initial x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How do you measure the percentage of oxygen?

A

react oxygen with another element
often a metal
air will gradually decrease in volume until all oxygen has been reacted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What might go wrong when investigating the percentage of oxygen in the air?

A

wasn’t done for long enough
leak in apparatus
- so not all oxygen was reacted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is element combustion?

A

element + oxygen -> element oxide

36
Q

What state is a metal oxide?

37
Q

What state is a non-metal oxide?

38
Q

What observations can be made when magnesium oxide forms?

A

bright white light
white powder

39
Q

What observations can be made when sulphur dioxide forms?

A

blue flame

40
Q

What observations can be made when water forms?

A

squeaky pop

41
Q

What is the chemical test for oxygen?

A

glowing splint relights

42
Q

What happens to water when a metal oxide dissolves in it?

A

becomes alkaline
pH 8-14

43
Q

What happens to water when a non-metal oxide dissolves in it?

A

becomes acidic
pH 0-6

44
Q

Define acid

45
Q

Define base

A

H+ acceptor

46
Q

Define alkali

47
Q

What is the difference between acid and acidic?

A

acid ; describes a substance in terms of ions
acidic ; pH of solution

48
Q

What is the difference between alkali and alkaline?

A

alkali ; describes a substance in terms of ions
alkaline ; pH of solution

49
Q

What happens when an acid reacts with water?

A

acid dissolves
donates H+
makes pH 0-6

50
Q

What happens when an alkali reacts with water?

A

alkali dissolves
donates OH-
makes pH 8-14

51
Q

What happens when a base reacts with water?

A

base dissolves
accepts H+ from H2O
OH- ion formed
makes pH 8-14

52
Q

What is the formula for hydrochloric acid?

53
Q

What is HCl?

A

hydrochloric acid

54
Q

What is the formula for nitric acid?

55
Q

What is HNO3?

A

nitric acid

56
Q

What is the formula for sulphuric acid?

57
Q

What is H2SO4?

A

sulphuric acid

58
Q

What is the formula for phosphoric acid?

59
Q

What is H3PO4?

A

phosphoric acid

60
Q

What is the formula for carbonic acid?

61
Q

What is H2CO3?

A

carbonic acid

62
Q

What is the formula for sodium hydroxide?

63
Q

What is NaOH?

A

sodium hydroxide

64
Q

What is the formula for potassium hydroxide?

65
Q

What is KOH?

A

potassium hydroxide

66
Q

What is the formula for ammonium hydroxide?

67
Q

What is NH4OH?

A

ammonium hydroxide

68
Q

What are soluble metal hydroxides?

69
Q

What is the formula for ammonia?

70
Q

What is NH3?

71
Q

What are some important bases?

A

all metal oxides
all metal hydroxides

72
Q

Define polyatomic ion

A

ion that contains more than one atom
released by acids

73
Q

What is the polyatomic ion released by nitric acid?

A

nitrate
NO3

74
Q

What is the polyatomic ion released by sulphuric acid?

A

sulphate
SO4

75
Q

What is the polyatomic ion released by phosphoric acid?

A

phosphate
PO4

76
Q

What is the polyatomic ion released by carbonic acid?

A

carbonate
CO3

77
Q

What is the reaction called between an acid and a base?

A

neutralisation

78
Q

What is neutralisation?

A

reaction between an acid and a base

79
Q

What is the equation of neutralisation?

A

acid + base -> water + salt

80
Q

What observations can be made during neutralisation?

A

base disappears
has been used up in reaction

81
Q

Describe crystallisation (4)

A
  1. add base to acid
  2. filter excess base
  3. heat salt solution until crystals form at edges
  4. leave to crystallise
82
Q

In crystallisation, why is excess base added?

A

ensure all acid is used up

83
Q

In crystallisation, why is the acid heated?

A

speed up reaction

84
Q

In crystallisation, why is the excess base filtered?

A

remove any solids before heating

85
Q

In crystallisation, how does heating make the crystals form?

A

saturates the solution

86
Q

What are the products in an acid + carbonate reaction?

A

salt, water and carbon dioxide

87
Q

What observations can be made in an acid + carbonate reaction?

A

carbonate disappears and is used up
effervescence because CO2 is produced

iGCSE Chemistry (17 decks)

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