flame tests

Question 1

how do we carry out a flame test

Answer 1

first place a small amount of the chemical onto wire mounted in a handle

place the end of this into a blue bunsen burner flame

the colour of the flame can be used to identify the metal ion present

Question 2

use colours to identify a metal ion present in a flame

Answer 2

crimson = lithium
yellow = sodium
lilac = potassium
orange-red = calcium
green = copper

Question 3

what are some problems with using flame tests to identify metal ions?

Answer 3

the colour of a flame test can be difficult to distinguish.
That is Especially true if there is only a low concentration of the metal compound

Sometimes a sample contains a mixture of metal ions which can mask the colour of the flame

Question 4

What techniques can scientists use to identify a metal ion besides the flame test?

Answer 4

flame emission spectroscopy

Question 5

describe the flame emission spectroscopy

Answer 5

A sample of the metal ions in solution is placed into a flame

the light given out is then passed into a machine called a spectroscope

The spectroscope converts the light into a line spectrum

The positions of the lines in the spectrum are specific for a given metal ion

We can use this to identify the metal ion in the sample

Question 6

What is an instrumental method

Answer 6

it is a method carried out by a machine

Question 7

What are the three main advantages to instrumental methods

Answer 7

instrumental methods are rapid. We could use flame emission spectroscopy to analyse samples more rapidly than we could using flame tests.

Instrumental methods are sensitive. flame emission spectra scope and you will work even on a tiny sample of metal compound

instrumental methods are accurate. Flame emission spectroscopy is more likely to identify a metal ion correctly than using a flame test