The \( M_{r} \) of the oxide formed in (b)(ii) was known to be \( 219.88gmol^{-1} \). Determine the molecular formula of the oxide formed, showing your working. Use section 7 of the data booklet.
The \( M_{r} \) of the oxide formed in (b)(ii) was known to be \( 219.88gmol^{-1} \). Determine the molecular formula of the oxide formed, showing your working. Use section 7 of the data booklet.