Analytical techniques

Question 1

How has global warming developed?

Answer 1

• electromagnetic radiation from sun absorbed by land and sea some radiation re-emitted as infrared
• greenhouse gases absorb radiation and re-emit it back to the earth (covalent bonds absorb radiation) called greenhouse effect
• human activities e.g. burning fossil fuels/landfills increases amount of greenhouse gases entering the atmosphere

Question 2

What evidence is used in global warming?

Answer 2

analysing sea water and air samples

Question 3

Define Infrared (IR) spectroscopy

Answer 3

uses infrared radiation to increase the vibrational energy of covalent bonds in a sample

Question 4

what does the frequency of infrared absorption by a covalent bond depend on?

Answer 4

• the type of atom on either side of the bond

- the position of the bond in the molecule

Question 5

What are the uses of IR spectroscopy?

Answer 5

• breathanalysers

- emission monitoring

Question 6

define m/z

Answer 6

mass of fragment divided by charge

Question 7

what do peaks show?

Answer 7

• fragments of the original molecule

- last peak is M+1 peak which is also the mr of the molecule