Mass Spectrometer And Spectrum

Question 1

What is a mass spectrometer used to find ?

Answer 1

To find relative masses eg
Ar, mr and isotopic abundance

Question 2

What is the acronym and the four stages of using a mass spectrometer

Answer 2

VIAD

1) vaporisation
2)ionisation
3)acceleration
4)detection

Question 3

Explain vaporisation

Answer 3

The sample is turned into a gas vapour by an electric heater

Question 4

Explain ionisation

Answer 4

The gas vapour particles are then bombarded by HIGH ENEERGY electrons —> electrons knock off particles —> leaving positive ions

Question 5

Explain acceleration

Answer 5

The positive ions are accelerated by a electric field

Question 6

Explain detection

Answer 6

-time taken for positive ions to reach detector depends on mass and charge

-high charged/lighter ions take quicker.

-lower charged/ heavier ions take longer

Question 7

What happens when a mass spectrometer is used ?

Answer 7

A mass spectrum graph is made

Question 8

What is on the y and x axis of the graph?

Answer 8

Y axis—> isotopic abundance of % isotopic abundance

X—> relative mass OR/and mass divided by charge

Question 9

How do you find out the ar using a mass spectrum graph??

Answer 9

-Times the y axis value by the x axis value
-add the values together and divide by 100 or TOTAL of isotopic abundance

Question 10

How do you find the% relative isotopic abundance when it’s not given??

Answer 10

-You get the value at the top of the peak
- diving by all the values (abundance)
-times by 100