Unit 5 Quiz Review

Question

The active ingredient in gasoline is Octane. Octane has a molecular mass of 114.26 g/mol and a empirical formula of C₄H₉. Use this data to find the molecular formula of Octane. 

 

Empirical formula molar mass =	_____ g	_______=	______g	=
	______g

Molecular Formula = C _{______} H _{_______}

Please fill in the boxes with the correct answers and explain.

Answer 1

n is a multiplier that converts empirical formulas to molecular formulas

(empirical formula)_n = molecular formula n is a whole number

n is found by dividing molar mass of the compound by the mass of the empirical formula

n = 114.26/molar mass of C₄H₉

molar mass of C4H9 is 57 g/mol

n = 114.26/57 = 2

molecular formula = (C₄H₉)₂ C₈H₁₈