Question

Write the name of the following compound and deduce its molecular mass.

CO₂

Answer 1

CO₂ - Carbon dioxide

Molecule	Constituent elements	Atomic mass u	Number of atoms in the molecule	Atomic mass × number of atoms	Mass of the Constituents u
CO2	C	12	1	12 × 1	12
	O	16	2	16 × 2	32

The molecular mass of CO₂ = Sum of Constituent atomic masses

(Molecular mass of CO₂) = (Atomic mass of C) × 1 + (Atomic mass of O) × 2

= (12 × 1) + (16 × 2)

= 12 + 32

= 44 u