A compound made up of two elements X and Y has an empirical formula `X_2Y`. If the atomic weight of X is 10 and that of Y is 5 and the compound has a vapour density 25, find the molecular formula,

Explanation

Molecular formula = `"(Empirical formula) "xx n`
`n=("Molecular formula weight")/("Empirical formula weight")= (2xxV.D.)/((2 xx 10+5))` (V.D. = Vapour Density)
= `(2 x 25)/(25)` = 2
`:.` Molecular formula = `(X_2Y) xx 2 = X_4Y_2`