Question

5. Desde 100 g de un compuesto formado por carbono, hidrogeno y oxígeno, se obtiene 39,132 g de agua y 95,656 g de CO2. Determine:
A. La fórmula empírica del compuesto.

Answer 1

Answer:

      $CH_2O_2$

Explanation:

The question in English is:

5. From 100 g of a compound formed by carbon, hydrogen and oxygen, 39.132 g of water and 95.656 g of CO₂ are obtained. Determine:

A. The empirical formula of the compound.

Solution

All the carbon of the compound ends as carbon in the CO₂ and all the hydrogen in the compound ends in the water.

1. C in CO₂

Divide the mass of CO₂ by its molar mass and multiply by the molar mass of C:

        $96.656g\times \dfrac{12.011g/mol}{44.01g/mol}=26.379gC$

2. H in H₂O

Divide the mass of H₂O by its molar mass and multiply by 2 times the molar mass of H:

        $39.132g\times \dfrac{(2\times 1.008)g/mol}{18.015g/mol}=4.379gH$

3. Calculate O by difference

     $100g-26.379g-4.379g=69.242gO$

4.Divide the mass of each element by the corresponding atomic mass to find the number of moles of the element

• C: 26.379g / (12.011g/mol) = 2.196 mol

• H: 4.379g / (1.008g/mol) = 4.344 mol

• O: 69.242g / (15.999g/mol) = 4.328 mol

5. Divide by the least number of moles

• C: 2.196/2.196 = 1

• H: 4.344 / 2.196 ≈ 2

• O: 4.328 / 2.196 ≈ 2

Those are the subscripts of the empirical formula:

6. Empirical formula

         $CH_2O_2$