11th Std Chemistry - - - - number of moles of ethane mol ethane mol CO mol CO = mole of ethane = . mole of ethane . H O + Fe + Fe + + H O (1e – × ) 1e – – – H O + 2Fe + → Fe + + H O ⇒ H O + 2Fe + + 2H + → 2Fe + + 2H O . Element Percentage Atomic mass Relative num- ber of atoms Simple ratio Whole no.
C . H . O . Empirical formula = C H O Molar mass Calculated empirical formula mass vapour density ∴ molecular formula (C H O) × = C H O 11th Std Chemistry 11th Std Chemistry - - - - .
Element % Relative no. of atoms Simple ratio Na . S . H .
O . ∴ Empirical formula = Na S H O molar mass calculated empirical formula mass Na S H O ( ) ( ) ( ) ( ) Molecular formula = Na S H O Since all the hydrogen in the compound present as water ∴ Molecular formula is Na SO . 10H O . (i) K Cr O K I H SO K SO Cr SO I H O