Question

Complete the following Empirical Formula & Molecular Formula problem:

Answer 1

Empirical formula is CCl.

Since the molar mass is provided, it is safe to assume that the empirical formula is not equal to the molecular formula.

We need to get the empirical weight to determine the multiple needed to arrive to the correct molecular formula.

Atom          Number in Molecule            Atomic Weight        Total Mass
C                              1                            12.0107                  12.0107
Cl                              1                            35.453                    35.453
                                                          total empirical weight    47.4637

Molecular weight / Empirical Weight
284.77 g/mol / 47.46 g/mol = 6 - the multiple needed to be multiplied with the empirical formula to get the molecular formula.

C has a molecular number of 1 =>  1 * 6 = 6  Thus C₆
Cl has a molecular number of 1 => 1 * 6 = 6 Thus Cl₆

Molecular Formula is C₆CL₆