Relative Atomic Mass and Relative Formula Mass

Question 1

Define Relative Atomic Mass (Ar)

Answer 1

The measure of how heavy the atom is compared to the atomic number
(the mass number)

Question 2

Define Relative Formula Mass (Mr)

Answer 2

The total mass of the individual atoms in the formula of a molecule.
(The Ars of a compound added together)

Question 3

Give the Relative Formula Mass of Sulphuric Acid

Answer 3

(2x1)+(1x32)+(4x16)

=98

Question 4

Give the Relative Fomrula Mass of Copper Hydroxide

Answer 4

(1x63.5)+(2x16)+(2x1)

=97.5

Question 5

Give the Relative Formula Mass of Aluminium Oxide

Answer 5

(2x27)+(3x16)

=102

Question 6

Give the Relative Formula Mass of Ammonium Sulphate

Answer 6

(2x7)+(8x1)+(1x16)+(4x8)

=70

Question 7

Define a mole

Answer 7

one mole of a substance is the Ar expressed in grams

Question 8

How do we calculate the number of moles?

Answer 8

No of moles = Mass/Mr

“No More Mr (nice guy)”