Moles I - Atoms, Molecules and Stoichiometry

Question 1

isotopes

Answer 1

atoms with the same number of protons but a different number of neutrons

Question 2

relative isotopic mass

Answer 2

the weighted mean mass of an isotope of an element relative to 1/12 the mass an atom of carbon-12

Question 3

relative atomic mass

Answer 3

the weighted mean mass of an atom of an element relative to 1/12 the mass of an atom of carbon-12

Question 4

relative molecular mass

Answer 4

the weighted mean mass of molecule of a substance relative to 1/12 the mass an atom of carbon-12

Question 4

relative formula mass (Mr)

Answer 4

the weighted mean mass of a formula unit of a substance relative to 1/12 the mass of an atom of carbon-12

Question 5

molar mass (and unit)

Answer 5

the mass in g of 1 mole of a substance, in gmol-1

Question 6

avogadro’s constant

Answer 6

6.022 x 10^23

Question 7

mole

Answer 7

the amount of a substance that contains 6.022 x 10^23 particles

Question 8

stoichiometry of n equation

Answer 8

relative number of moles of each substance involved in a reaction

Question 9

what is mass spectrometry used for?

Answer 9

to measure the mass of an individual particle and count the relative number of atoms of a given mass

Question 10

5 steps of mass spectrometry

Answer 10

1. inject particles
2. ionise particles
3. accelerate particles
4. deflect particles
5. detect particles