What is the molecular formula of a compound given the molar mass of the compound is 186.5g and the empirical formula is C2H7?

Answer 1

The molecular mass is C2H7

you have 186.5 g of the substance, so calculate

2(12.01)+7(1.01)=31.09

so 186.5/31.09=6

so you can say C12H42

but when you divide 2 by 2 and 7 by 2 you obtain 1 and 3.5 because you have 3.5 you have to multiplied by 2 again, so you obtain the same formula as the empirical formula.

It example is the same as water, which empirical formula es H2O as its molecular formula