Determine the molecular formula of an oxide of iron in which the mass per cent of iron and oxygen are 69.9 and 30.1 respectively (molecular mass is 159.8).

Explanation

To determine the empirical formula of the oxide of iron
Empirical formula of the compound`=Fe_(2)O_(3)`
Let, molecular formula of the compound be `(Fe_(2)O_(3))_(n)`
`therefore` Molecular mass of the compound
`=nxx[2xx55.85+3xx16.00]=159.7n`
`therefore`As given in the question, `nxx159.7=159.8 or n=1`.
`therefore` Molecular formula of the compound is `Fe_(2)O_(3)`.