Relative Atomic Mass and Relative Molecular Mass

Question 1

How do you work out the relative atomic mass?

Answer 1

average mass of one atom of an element multiplied by 12 all divided by the mass of one atom of carbon 12

Question 2

What is the definition of the relative atomic mass?

Answer 2

The relative atomic mass is the weighted average mass of an atom of an element, taking into account its naturally occurring isotopes, relative to 1/12 the relative atomic mass of an atom of carbon - 12

Question 3

How do you work out the relative molecular mass?

Answer 3

average mass of one molecule multiplied by 12 all divided by the mass of one atom of carbon 12

Question 3

What is the definition of the relative molecular mass?

Answer 3

The relative molecular mass of a molecule is the mass of that molecule compared to 1/12 the relative atomic mass of an atom of carbon - 12

Question 4

How do you find the relative molecular mass?

Answer 4

You would add up all the relative atomic masses of all the atoms present in a molecule

Question 5

Find the relative molecular mass of water (H2O)

Answer 5

Hydrogen = 1
Oxygen = 16

(1x2) + 16 = 18

18 is the relative molecular mass

Question 6

What is the relative formula mass used for and why?

Answer 6

The relative formula mass is used for ionic compounds beceause they do not exist as molecules

Question 7

Find the relative formula mass of sodium sulfate (Na2SO4)

Answer 7

Sodium (Na) = 23
Sulfur (S) = 32.1
Oxygen (O) = 16

(23x2) + 32.1 + (16x4)

46 + 32.1 + 64 = 142.1