extra deck: flame tests

Question 1

Colour of the Lithium ion’s flame

Answer 1

Crimson

Question 2

Colour of the sodium ion’s flame

Answer 2

Yellow

Question 3

Colour of the potassium ion’s flame

Answer 3

Lilac

Question 4

Colour of the calcium ion’s flame

Answer 4

Orange-red

Question 5

Colour of the copper ion’s flame

Answer 5

Green

Question 6

What are the problems of flame tests?

Answer 6

• colour can be difficult to distinguish
• especially if there’s a low concentration of the metal compound
• sometimes a sample contains a mixture of ion’s and this can mask the flame

Question 7

What could scientists use instead of flame tests for more reliable results?

Answer 7

-flame emission spectroscopy

Question 8

How does flame emission spectroscopy work?

Answer 8

• sample of the metal ion 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 so we can use this to identify the metal ion in the sample

Question 9

How is flame emission spectroscopy more reliable?

Answer 9

-the position of the lines in the spectrum are specific for a given metal ion

Question 10

Other than which ion, what can flame emission spectroscopy also tell us?

Answer 10

-the concentration of the metal ion

Question 11

How does flame emission spectroscopy show higher concentrations of ions?

Answer 11

-more intense lines

Question 12

Advantages of instrumental methods:

Answer 12

• they are RAPID, more rapid than other methods
• they are SENSITIVE and work even on tiny samples of metal compound
• they are ACCURATE more correct than other methods