2A.2 Mass spectrometry

Question 1

what is the relative atomic mass2

Answer 1

it is the mean mass of one atom compared to 1/12 of the mass of an atom of carbon 12 isotope

Question 2

what is the reative isotopic masses

Answer 2

the mass of an indivual atom of a particle isotope relative to 1/12 of the mass of an atom of carbon 12. (they are different from number Z and are most likely not to be a whole number since there relative to 1/12)

Question 3

how can we find relative atomic mas using relative isotopic mass and percentage abundance

Answer 3

(relative isotopic mass x percenatge abundance) / 100 (it should always be between the relative isotopic masses)

Question 4

what is mass spectrometer

Answer 4

it measures the masses of atoms and molecules and also displays the relitive abundances

Question 5

how does mass spectrometer work

Answer 5

1. Ionisation:
   Produces positive ions Positive ions = positive atoms, molecules or fragments of molecules
   Fragments of molecules useful in analysing organic compounds.
2. Acceleration:
   Electric field causes positive ions to accelerate.
3. Deflection:
   Positive ions are deflected by magnetic field according m/z (mass to charge ratio)
   Amount a positive ion is deflected by magnetic depends on its “mass to charge ratio”
   Relative mass of the ion, m, divided by its charge, z
   Ions with small m/z values are deflected less that ions with large m/z values
4. Detection
   The beam of ions passing through the machine is detected electrically.
   Measures masses of atoms and molecules or m/z ratio.
   Calculates the relative abundance of each positive ion and displays as percentage
5. Spectra is produced showing:
   Intensity (abundance) vs m/z ratio.

Question 6

how can you calculate the relitive atomic mass of diotomic molecule

Answer 6

by observing its relative abundance on the graph of mass spectrometer, so compare the abundance of the two get a ratio multiple by the ratio number of each then divide by the 2 values in the ratio added together

Question 6

how can you calculate the relitive atomic mass of diotomic molecule

Answer 6

by observing its relative abundance on the graph of mass spectrometer, so compare the abundance of the two get a ratio multiple by the ratio number of each then divide by the 2 values in the ratio added together

Question 6

how can you calculate the relitive atomic mass of diotomic molecule

Answer 6

by observing its relative abundance on the graph of mass spectrometer, so compare the abundance of the two get a ratio multiple by the ratio number of each then divide by the 2 values in the ratio added together

Question 7

how can we calculate the molecular masses of a diotomic molecule

Answer 7

by comapring teh masses number and using probability to find the raition then multiplying each mass number with its ratio then dividing by the sun of all the values in the ratio

Question 8

how can we find the relative atomic mass of polytomic molecule

Answer 8

by finding the molecular ion peak

Question 9

molecular ion peak

Answer 9

the peek with the highest m/z ratio in the mass spectrum (the M peak)

Question 10

what is the M+1 peak

Answer 10

it is a small percentageof carbon 13 which its peaks become significant in molecules with large masses but with small masses the peak is small and insignificant ( it only appears in organic compounds)

Question 10

what is the M+1 peak

Answer 10

it is a small percentageof carbon 13 which its peaks become significant in molecules with large masses but with small masses the peak is small and insignificant

Question 11

along with the M+1 peak is there any other fragments

Answer 11

yes the Hydrogen small fragments