C12.6 Instrumental analysis

Question 1

What are some benefits of modern instrumental methods over older methods?

Answer 1

They are highly accurate and sensitive
They are quicker
They enable very small samples to be analysed

Question 2

What are the main disadvantages of using instrumental methods?

Answer 2

It is usually very expensive
Takes special training to use
Gives results that can often be interpreted only by comparison with data from know substances?

Question 3

What is the purpose of using flame emission spectroscopy?

Answer 3

Analyse samples for metal ions

Question 4

How is flame emissions spectroscopy carried out?

Answer 4

The sample is heating in a flame
The energy provided excites electrons in the metal ions - making them jump into higher energy levels
When they fall back to a lower energy level - the energy is released as light energy

Question 5

What is the purpose of a spectroscope?

Answer 5

To analyse the wavelengths of the light produced in the spectrometer

Question 6

What is the line spectrum?

Answer 6

Each type of metal ion absorbs and gives out its own characteristic pattern of radiation

Question 7

How can the concentration of the metal ions present in a sample be determined?

Answer 7

The spectrometer can measure the intensity of light with a specific wavelength known to be characteristic of a particular metal ion

Question 8

What are the benefits of using flame emission spectroscopy?

Answer 8

Can provide accurate ways to monitor water for metal ions

Mercury is a dangerous toxin that can build up in your body - therefore it needs to be detected

Question 9

What is the use of flame emission spectrometers in the steel industry?

Answer 9

Steel is a mixture of elements with iron

The steelmakers need to control carefully the amount of trace metals present - as the quality of steel depends on this