Question

State the information obtained from the chemical formula of a compound.

Answer 1

The chemical formula of a compound is a shorthand way of representing its molecule. The information that can be obtained from the chemical formula of a compound are:

1) Types of elements present in the compound (0.5 mark)
2) Number of each kind of atoms in a molecule of the compound (0.5 mark)
3) Ratio of different atoms in a molecule of the compound (0.5 mark)
4) Mass of a molecule​ of the compound (0.5 mark)

For example, the chemical formula of the compound water is ${\text{H}}_2$$\text{O}$. This shows the presence of two constituent elements, hydrogen and oxygen. Two atoms of hydrogen and one atom of oxygen combine to form a molecule of water. The ratio in which the atoms of hydrogen and oxygen combine to form a molecule of water is 2:1. Moreover, the mass of a water molecule can be calculated by adding the mass of two hydrogen atoms and one oxygen atom. (2 marks)