A compound is 92.2% Carbon and 7.76% Hydrogen. The formula mass of the compound is 78.1 g. Calculate the empirical formula and molecular formula of the compound.

The empirical formula of the compound is CH. The molecular formula of the compound is

A molecular formula has been the one that represents the exact number of atoms in a compound. The empirical formula has been able to represent the whole number ratio of atoms present in a compound.

The given compound has 92.2% Carbon and 7.76% Hydrogen. The weight will be:

Carbon = 92.2 g

Hydrogen = 7.76 g

From the weight, the moles of elements in the compound can be calculated.

Moles =

Moles of carbon =

Moles of carbon = 7.76 moles

Moles of hydrogen = weight of hydrogen

Moles of hydrogen = 7.76 moles

For the empirical formula, divide the moles of each element to the nearest mole number;

Carbon =

Carbon = 1

Hydrogen =

Hydrogen = 1

Thus, the empirical formula of the compound will be CH.

For finding the molecular formula, the molecular weight from the empirical formula has been divided with the molecular weight of the compound to find the number of atoms.

Molecular weight of empirical formula = weight of carbon + weight of hydrogen

Molecular weight of empirical formula = 12 + 1

Molecular weight of empirical formula = 13 grams

Molecular mass of compound = 78.1 grams.

Number of atoms of each element =

Number of atoms of each element = 6

Thus, the molecular formula of the compound is .

For more information about the molecular and empirical formula, refer to the link:

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The answer to your question is empirical formula = CH

                                                    molecular formula = C₆H₆

Explanation:

Data

Carbon  92.2%

Hydrogen  7.76%

Formula mass = 78.1 g

Process

1.- Express the percents as grams

Carbon            92.2 g

Hydrogen          7.76 g

2.- Convert the grams to moles

Carbon                 12 g 1 mol

                            92.2 g  x

                            x = (92.2 x 1)/12

                            x = 7.68 moles

Hydrogen             1 g 1 mol

                            7.76 g  x

                            x = 7.76 moles

3.- Divide by the lowest number of moles

Carbon         7.68 / 7.68 = 1

Hydrogen     7.76 / 7.68 = 1.01

4.- Write the empirical formula

                                      CH

5.- Calculate the molecular weight of the empirical formula

CH = 12 + 1 = 13

6.- Divide the molecular weight by the molecular weight of the empirical formula

                78.1 / 13 = 6

7.- Write the molecular formula

               6(CH) = C₆H₆