Topic 5b- Moles (paper 1 +2)

Question 1

What is 1 mole equal to?

Answer 1

6.02 x 10²³

Question 2

How does relative atomic mass relate to the number of moles in a substance?

Answer 2

The relative atomic mass number is equal to how many grams of a substance contains one mole.
e.g. Na’s atomic mass = 23
Therefore:
23 grams of Na = 1 mole (6.02 x 10²³) of Na atoms

Question 3

What is the formula for moles of atoms?

Answer 3

moles of atoms = mass / relative atomic mass
(relative atomic mass in grams)
n = m/ Ar

Question 4

What is the molecular mass of a compound?

Answer 4

The sum of all the masses of all the atoms in a formula- e.g.
CaCO₃
RFM = 40 + 12 + (3 x 16)