1.43​ ​Calculate​ ​relative​ ​formula​ ​mass​ ​given​ ​relative​ ​atomic​ ​masses

Question 1

What is the relative formula mass (Mr) of a compound?

Answer 1

The sum of the relative atomic masses of the atoms in the numbers shown in the formula.

Question 2

How do you calculate the relative formula mass for multiple atoms of an element?

Answer 2

You need to multiply the atomic mass by the number of atoms present in the compound.

For example, in CaCl2, there are 2 atoms of chlorine, so you need to add on 35.5 x 2.

Question 3

What is the relationship in a balanced chemical equation regarding Mr?

Answer 3

The sum of Mr of reactants in quantities shown equals the sum of Mr of products in quantities shown.