A brominated alkane an analysis gave 12.8% carbon and 2.1%H. If its vapour density is 93.95, what is its molecular formula?

A brominated alkane an analysis gave 12.8% carbon and 2.1%H. If its va

1.	A brominated alkane an analysis gave 12.8% carbon and 2.1%H. If its vapour density is 93.95, what is its molecular formula?
Answer» Solution :PERCENT weight of bromium = 100-(%C+%H) = 100-14.9 = 85.1 C : H: Br `=(12.8)/(12) : (2.1)/(1) : (85.1)/(80) = 1 : 2 : 1 ` Empirical formula is `CH_(2)Br` Molecular weight `= 2xxV.D. = 2xx93.95 = 187.9` ` n = (187.9)/(94) = 2` Molecular formula `=2xxCH_(2)Br = C_(2)H_(4)Br_(2)`