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Flashcards in Test for ions and radicals Deck (95)
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1
Q

Thiosulphate: equation

A

S₂O₃2-

2
Q

Thiosulphate: reagent

A

Add dilute HCl to get four products.

3
Q

Thiosulphate: observations

A
  • A yellow precipitate of sulphur forming.
  • Sulfur dioxide gas given off = distinct smell as it is quite pungent.
  • the ppt is sulphur (S)
4
Q

Thiosulphate: How to identify sulphur dioxide gas

A

By putting a spot of potassium permanganate on filter paper and hold over reaction, purple colour disappears as sulphur dioxide acts as a reducing agent reducing Mn (+7) which is purple to Mn (+2) which is colourless.

5
Q

Sulphate equation

A

SO₄2-

6
Q

Sulphate reagent

A

Add barium chloride solution, a white ppt of barium sulfate is formed.

7
Q

Sulfate - why is dilute HCl added?

A

To distinguish - no reaction (white ppt remains) as barium sulphate is insoluble in dilute acid.

8
Q

Sulphite equation

A

SO₃2-

9
Q

Sulphite reagent

A

Add barium chloride solution, a white ppt of barium sulfite is formed.

10
Q

Sulphite - to distinguish between the two precipitates.

A

Add dilute HCl solution to distinguish, the ppt disappears and sulphur dioxide gas is given off if a sulfite ion is present.

11
Q

Sulphite reaction - what happens if you add dilute HCl solution to the white ppt of barium sulfate?

A

The ppt remains as no reaction occurs.

12
Q

Carbonate and hydrogen carbonate equations.

A

CO₃2- and HCO₃-

13
Q

Carbonate and hydrogen carbonate reaction - reagent.

A

Add dilute acid

14
Q

Carbonate and hydrogen carbonate: what happens when you add dilute acid and how do you know?

A

if a carbonate or hydrogen carbonate is present then carbon dioxide will be given off and can be noted by light effervescence

15
Q

Carbonate and hydrogen carbonate: how to test for CO2 gass

A

bubble the carbon dioxide through a colourless solution of limewater. it turns milky white

16
Q

what is limewater?

A

an aqueous solution of calcium hydroxide

17
Q

to distinguish between a Carbonate and hydrogen carbonate: reagent

A

add magnesium sulfate to both

18
Q

formula for magnesium sulfate

A

MgSO4

19
Q

to distinguish between a Carbonate and hydrogen carbonate: if a carbonate is present

A

white ppt is produced - magnesium carbonate

20
Q

to distinguish between a Carbonate and hydrogen carbonate: if a hydrogen carbonate is present and why

A

no ppt present as magnesium hydrogen carbonate is soluble in the solution

21
Q

what happens if you boil magnesium hydrogen carbonate and why

A

you get a white ppt as hydrogen carbonates decompose on heating

22
Q

Nitrate: reagents

A

freshly made Iron (II) sulphate solution

concentrated H2SO4

23
Q

Nitrate: H2SO4

A

sulphuric acid

24
Q

Nitrate: is there a ppt in aqueous nitrate solution and why

A

no because nitrate ion is soluble in water

25
Q

Nitrate: what colour is the fresh Iron (II) sulphate solution

A

a greenish colour

26
Q

Nitrate: how do you add the conc. H2SO4 soln.?

A

slowly ad carefully down the inside of the test tube

27
Q

Nitrate: what falls to the bottom of the test tube?

A

the sulphuric acid

28
Q

Nitrate: how do you confirm that it’s a nitrate

A

a brown ring forms at the junction of the substances

29
Q

Nitrate: formula for the substance that is the brown ring

A

FeSO4.NO

30
Q

Nitrate: formula for nitrate ion

A

NO3-

31
Q

chloride: ion

A

Cl-

32
Q

chloride: reagents

A

silver nitrate solution and concentrated nitric acid

33
Q

chloride: confirmation

A

immediate white ppt forms

34
Q

chloride: why is the reaction immediate

A

it is an ionic reaction

35
Q

chloride: what does the immediate formation of the white ppt tell us?

A

that there are chloride ions present in the aqueous soln. tested

36
Q

phosphate: ion

A

PO4 3-

37
Q

phosphate: reagents

A

ammonium molybdate and 5 drops of conc. nitric acid

38
Q

phosphate: what condition is needed?

A

heat gently

39
Q

phosphate: confirmation

A

yellow ppt. forms

40
Q

phosphate: name of yellow ppt.

A

ammonium phosphomolybdate

41
Q

Thiosulphate: equation for the thiosulphate molecule

A

Na2S2O3

42
Q

Thiosulphate: equation for hydrochloric acid

A

HCl

43
Q

Thiosulphate: equation for sodium chloride

A

NaCl

44
Q

Thiosulphate: equation for sulphur dioxide gas

A

SO2 (↑)

45
Q

Thiosulphate: equation for water

A

H2O

46
Q

Thiosulphate: equation for sulphur ppt

A

S (↓)

47
Q

Thiosulphate: balanced equation for complete reaction

A

Na2S2O3 + 2HCl -> 2NaCl + SO2 (↑) + H2O + S (↓)

48
Q

Thiosulphate: 3 products

A

sodium chloride
sulphur dioxide gas
sulphur

49
Q

sulphate: equation for ion

A

SO4 2-

50
Q

sulphate: equation for molecule with sulphate

A

Na2SO4 (aq)

51
Q

sulphate: equation for barium chloride

A

BaCl2 (aq)

52
Q

sulphate: equation for barium sulphate

A

BaSO4 (↓) (s)

53
Q

sulphate: equation for sodium chloride

A

NaCl (aq)

54
Q

sulphate: equation for complete equation

A

Na2SO4 (aq) + BaCl (aq) -> BaSO4 (↓) (s) + 2NaCl (aq)

55
Q

sulphate: which is the ppt?

A

BaSO4 barium sulphate

56
Q

sulphite: equation for molecule with sulphite

A

Na2SO3 (aq)

57
Q

sulphite: equation for barium chloride

A

BaCl2 (aq)

58
Q

sulphite: equation for barium sulphite

A

BaSO3 (↓) (s)

59
Q

sulphite: equation for sodium chloride

A

2NaCl (aq)

60
Q

sulphite: equation for complete reaction

A

Na2SO3 (aq) + BaCl2 (aq) -> BaSO3 (↓) (s) + 2NaCl (aq)

61
Q

sulphite: what is the ppt

A

BaSO3 (↓) (s)

barium sulphite

62
Q

sulphite: what are the 2 products

A

BaSO3 (↓) (s)

2NaCl (aq)

63
Q

to distinguish between a sulphate and sulphite: complete equation

A

BaSO3 (s) + 2 HCl (aq) -> BaCl2 (aq) + H2O (l) + SO2 (↑) (g)

64
Q

carbonate: equation for molecule with carbonate ion in it

A

Na2CO3 (aq)

65
Q

carbonate: equation for hydrochloric acid

A

HCl (aq)

66
Q

carbonate: equation for sodium chloride

A

NaCl (aq)

67
Q

carbonate: equation for water

A

H2O (l)

68
Q

carbonate: equation for carbon dioxide

A

CO2 (↑) (g)

69
Q

carbonate: equation for complete reaction

A

Na2CO3 (aq) + 2HCl (aq) -> 2NaCl (aq) + H2O (l) + CO2 (↑) (g)

70
Q

hydrogen carbonate: equation for molecule with hydrogen carbonate ion in it

A

NaHCO3 (aq)

71
Q

hydrogen carbonate: equation for hydrochloric acid

A

HCl (aq)

72
Q

hydrogen carbonate: equation for sodium chloride

A

NaCl (aq)

73
Q

hydrogen carbonate: equation for water

A

H2O (l)

74
Q

hydrogen carbonate: equation for carbon dioxide

A

CO2 (↑) (g)

75
Q

hydrogen carbonate: equation for complete reaction

A

NaHCO3 (aq) + HCl (aq) -> NaCl (aq) + H2O (l) + CO2 (↑) (g)

76
Q

to test for carbon dioxide gas: equation for carbon dioxide

A

CO2 (g)

77
Q

to test for carbon dioxide gas: equation for limewater

A

Ca(OH)2 (aq)

78
Q

to test for carbon dioxide gas: equation for calcium carbonate

A

CaCO3 (↓) (s)

79
Q

to test for carbon dioxide gas: equation for water

A

H2O (l)

80
Q

to test for carbon dioxide gas: equation for complete reaction

A

CO2 (g) + Ca(OH)2 (aq) -> CaCO3 (↓) (s) + H2O (l)

81
Q

to test for carbon dioxide gas: what was the ppt

A

CaCO3 (↓) (s)

82
Q

to distinguish between a Carbonate and hydrogen carbonate: equation for complete reaction between the reagent magnesium sulphate and the CARBONATE ion

A

Na2CO3(aq) + MgSO4 (aq) -> MgCO3 (↓) (s) + Na2SO4 (aq)

83
Q

to distinguish between a Carbonate and hydrogen carbonate: if there is a white ppt it is a

A

carbonate

84
Q

what is the ppt that proves the carbonate

A

MgCO3 (↓) (s) magnesium carbonate

85
Q

to distinguish between a Carbonate and hydrogen carbonate: equation for complete reaction between the reagent magnesium sulphate and the HYDROGEN CARBONATE ion

A

NaHCO3(aq) + MgSO4 (aq) -> Mg(HCO3)2 (aq) + Na2SO4 (aq)

86
Q

equation for when you boil Mg(HCO3)2

A

Mg(HCO3)2 –heat–> MgCO3 (↓) + H2O+ CO2 (↑)

87
Q

nitrate: equation for iron (II) sulphate

A

FeSO4

88
Q

nitrate: equation for sulphuric acid

A

H2SO4

89
Q

chloride: equation for molecule with chloride in it

A

NaCl (aq)

90
Q

chloride: equation for silver nitrate

A

AgNO3 (aq)

91
Q

chloride: equation for nitric acid

A

HNO3 (aq)

92
Q

chloride: equation for sodium nitrate

A

NaNO3 (aq)

93
Q

chloride: equation for silver chloride

A

AgCl (↓)(s)

94
Q

chloride: what is the white ppt

A

AgCl (↓)(s) silver chloride

95
Q

phosphate: equation for nitric acid

A

HNO3

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