Question

A compound containing 5.9265% H
and 94.0735% O has a molar mass of
34.01468 g/mol. Determine the
empirical and molecular formulas.

Answer 1

Answer:

Molecular formula = H₂O₂

Empirical formula = OH

Explanation:

Given data:

Percentage of hydrogen = 5.9265%

Percentage of oxygen = 94.0735%

Molar mass of compound = 34.01468 g/mol

Empirical formula = ?

Molecular formula = ?

Solution:

Number of gram atoms of H = 5.9265 / 1.01 = 5.87

Number of gram atoms of O = 94.0735 / 16 = 5.88

Atomic ratio:

              H                    :            O

             5.87/5.87        :          5.88/5.87

                   1                  :            1

H : O = 1 : 1

Empirical formula is OH.

Molecular formula:

Molecular formula = n (empirical formula)

n = molar mass of compound / empirical formula mass

Empirical formula mass  = OH = 16+1.01 = 17.01

n =  34.01468/ 17.01

n = 2

Molecular formula = n (empirical formula)

Molecular formula = 2 (OH)

Molecular formula = H₂O₂