If the molecular mass of the potassium and oxygen compound in ex. 31 is 94 g/mol, what is the molecular formula for this compound?

Answer is: the molecular formula for this compound is K₂O.

M (KₓOₐ) = 94 g/mol; molecula mass of the unknown compound.

M (KₓOₐ) = x·Ar (K) + a·Ar (O) · g/mol.

94 g/mol = 39·x + 16·a · g/mol.

Only possible solution is x = 2 and a = 1.

94 g/mol = 39 · 2 + 16 · 1 · g/mol.

Ar is relative atomic mass (the ratio of the average mass of atoms of a chemical element to one unified atomic mass unit) of an element.