A compound has a molar mass of 86.0 g/mol and an empirical formula of C3H7 what is the molecular formula

The formula for the molecular formula is molar mass / empirical formula

So, the empirical formula of C3H7 is equal to C*3 + H*7 which is equal to 12*3 + 7. Then use the molecular formula = 86 / (12*3+7) = 2

Therefore, the molecular formula is 2 times the empirical formula which is C6H14.