Brainscape's Knowledge GenomeTM

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


See full index

AQA GCSE Chem!! > Chemical Analysis: Identification of Ions > Flashcards

Chemical Analysis: Identification of Ions Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Geography - AQA flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

potassium ions

A

K+

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

what colour flame do potassium ions produce?

A

lilac

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

copper ions

A

Cu2+

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

what colour flame do copper 2+ ions produce?

A

green

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

sodium ions

A

Na+

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

what colour flame do sodium ions produce?

A

yellow

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

calcium ions

A

Ca2+

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

what colour flame do calcium ions produce?

A

orange-red flame

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

lithium ions

A

Li+

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

what colour flame do lithium ions produce?

A

crimson

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

why are flame tests used?

A

to identify metal ions in ionic compounds

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

flame test practical steps

A
  1. submerge nichrome wire loop in dilute HCl to clean it
  2. place nichrome wire into sample being tested
  3. hold nichrome wire loop in bunsen burner’s blue flame
  4. observe change in colour of bunsen burner flame
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what colour precipitate do magnesium ions (Mg2+) form?

A

white precipitate magnesium hydroxide

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

magnesium hydroxide equation

A

Mg2+ (aq) + 2OH- (aq) –> Mg(OH)2 (s)

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

what colour precipitate do aluminium ions (Al3+) form?

A

white precipitate aluminium hydroxide

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

aluminium hydroxide equation

A

Al3+ (aq) + 3OH- (aq) –> Al(OH)3 (s)

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

what does aluminium hydroxide dissolve in?

A

excess NaOH (forms colourless solutions)

18
Q

what colour precipitate do calcium ions (Ca2+) form?

A

white precipitate calcium hydroxide

19
Q

calcium hydroxide equation

A

Ca2+ (aq) + 2OH- (aq) –> Ca(OH)2 (s)

20
Q

what colour precipitate do iron ions (Fe2+) form?

A

green precipitate iron (II) hydroxide

21
Q

iron (II) hydroxide equation

A

Fe2+ (aq) + 2OH- (aq) –> Fe(OH)2 (s)

22
Q

what colour precipitate do iron ions (Fe3+) from?

A

brown precipitate iron (II) hydroxide

23
Q

iron (III) hydroxide equation

A

Fe3+ (aq) + 3OH- (aq) –> Fe(OH)3 (s)

24
Q

what colour precipitate do copper ions (Cu2+) form?

A

blue precipitate copper (II) hydroxide

25
Q

copper (II) hydroxide equation

A

Cu2+ (aq) + 2OH- (aq) –> Cu(OH)2 (s)

26
Q

Test for carbonates?

A
  • add dilute acid to sample
  • CO2 will be produced, observed by effervescence
  • bubble gas through limewater to test it
27
Q

what do all carbonates produce?

A

CO3 2-

28
Q

how to test for halides?

A
  • add dilute nitric acid to unknown solution (removes carbonate ions to ensure they don’t form a precipitate)
  • add dilute silver nitrate
  • if halide ions are present, they will form a white precipitate with silver ions
29
Q

what colour precipitate is silver chloride?

A

white

30
Q

silver chloride equation

A

Ag+ (aq) + Cl- (aq) –> AgCl (s)

31
Q

what colour precipitate is silver bromide?

A

cream

32
Q

silver bromide equation

A

Ag+ (aq) + Br- (aq) –> AgBr (s)

33
Q

what colour precipitate is silver iodide?

A

pale yellow

34
Q

silver iodide equation

A

Ag+ (aq) + I- (aq) –> AgI (s)

35
Q

how to test for sulfates?

A
  • add dilute HCl to unknown sample (removes carbonate ions which could disrupt results by forming a precipitate)
  • add barium chloride solution
  • white precipitate forms if sulfates are present
36
Q

what colour precipitate does barium sulphate form?

A

white

37
Q

barium sulphate equation

A

Ba2+ (aq) + SO4 2- (aq) –> BaSO4 (s)

38
Q

advantages of using instrumental methods of chemical analysis

A

greater sensitivity and accuracy
- quicker at producing results
- able to analyse tiny samples

39
Q

disadvantages of using instrumental methods of chemical analysis

A
  • expensive
  • must go through special training to operate the instruments
  • only useful when compared to data from known substances
40
Q

how does flame emission spectroscopy work?

A
  1. place sample of metal solution being tested into a flame, light will be given off
  2. light given off is captured in a spectroscope - instrument generates a line spectrum by distinguishing between light with different wave lengths
41
Q

what does a flame emission spectroscopy analyse?

A
  • identity of metal ions (metal ions generate new lines on spectrum so can identify all ions present in solution)
  • concentration of metal ions (intensity of line)
  • reference spectra (analyse mixtures by comparing them with reference spectra)

AQA GCSE Chem!! (1 decks)

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