Brainscape's Knowledge GenomeTM

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


See full index

GCSE Edexcel Separate Chemistry > SC25 Qualitative Analysis > Flashcards

SC25 Qualitative Analysis Flashcards

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

What is a flame test used for?

A

To identify metal ions by the colour of the flame they produce

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

Describe how to carry out a flame test

A
  1. Clean a wire loop by dipping it into HCL and then holding it in a blue flame until it burns without altering the colour of the flame
  2. Dip the clean wire loop into the unknown salt and then hold the loop in the blue flame of a Bunsen burner. Record the colour
  3. Repeat for other unknown samples
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What colour flame does Lithium produce as the outcome of a flame test?

A

Red

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

What colour flame does Potassium (K+) produce as the outcome of a flame test?

A

Lilac

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

What colour flame does Sodium (Na+) produce as the outcome of a flame test?

A

Yellow

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

What colour flame does Calcium (Ca2+)
produce as the outcome of a flame test?

A

Orange-red

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

What colour flame does Copper (Cu2+) produce as the outcome of a flame test?

A

Blue-green

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

Give some examples of instrumental methods

A
  • Gas chromatography
  • Mass spectrometry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the advantages of using instrumental methods?

A

Accurate, sensitive and rapid

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

How can metal cations that are dissolved in a solution be identified?

A

Through the colour of the precipitate formed after the addition of sodium hydroxide

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

Describe how to carry out a hydroxide precipitate test

A
  1. Place a little of the unknown solution in a test tube and add a few drops of dilute sodium hydroxide solution. Record any observations
  2. If a white precipitate forms, add an excess of sodium hydroxide and record any observations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the effect of adding sodium hydroxide to aluminium?

A

Forms a white precipitate, dissolves in excess NaOH to form a colourless solution

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

What is the effect of adding sodium hydroxide to calcium?

A

White precipitate, insoluble, so remains in excess sodium hydroxide

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

What is the effect of adding sodium hydroxide to copper?

A

Light blue precipitate, insoluble in excess

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

What is the effect of adding sodium hydroxide to iron II?

A

Green precipitate, insoluble in excess

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

What is the effect of adding sodium hydroxide to iron III?

A

Red-brown precipitate, insoluble in excess

17
Q

How can we test for ammonium ions using sodium hydroxide?

A
  1. Gently heat the solution after adding the NaOH
  2. If ammonium ion is present, it produces ammonium gas and can be tested with red litmus paper
18
Q

What is the chemical test for ammonia?

A

Turns red litmus paper blue

19
Q

Describe the test for ammonia using HCl

A
  1. React the gas with HCl
  2. A white smoke is produced if ammonium gas is present of ammonium chloride
20
Q

How can we test for the presence of a carbonate ion?

A

Bubble the gas through limewater or any dilute acid. If the limwater goes cloudy, it indicates the presence of CO2

21
Q

How can we test for the presence of a sulfate ion?

A
  1. Add dilute HCl followed by a barium chloride solution
  2. A white precipitate of barium sulfate will form when sulfate ions are in the solution
22
Q

How can we test for the presence of halide ions?

A
  1. Add dilute nitric acid followed by the addition of silver nitrate solution
  2. This will form a silver halide precipitate
  3. Depending on the halide present, a different colour precipitate is formed, allowing us to identify the halide ion
23
Q

What colour does chloride turn when added to a silver precipitate?

A

White

24
Q

What colour does bromide turn when added to a silver precipitate?

A

Cream

25
Q

What colour does iodine turn when added to a silver precipitate?

A

yellow

26
Q

How does flame photometry work?

A

By exposing the sample to a very hot flame and then measuring the intensity and wavelength of the light emitted

27
Q

What is the output of flame photometry?

A

An emission spectrum

28
Q

What is the emission spectrum used for?

A

To identify the metal ions in the solution and measure their concentrations

GCSE Edexcel Separate Chemistry (23 decks)

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