Show that the empirical formula of the compound is CH2O in the following case:A 2.203 g sample of an organic compound was extracted from a plant. When it was burned in oxygen, the hydrogen in the...

Show that the empirical formula of the compound is CH2O in the following case:

A 2.203 g sample of an organic compound was extracted from a plant. When it was burned in oxygen, the hydrogen in the compound was converted to 1.32 g of water and the carbon was oxidized to 3.23 g of carbon dioxide.

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justaguide | College Teacher | (Level 2) Distinguished Educator

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A 2.203 g sample of an organic compound was extracted from a plant. When it was burned in oxygen, the hydrogen in the compound was converted to 1.32 g of water and the carbon was oxidized to 3.23 g of carbon dioxide.

Assuming the organic compound consists of only carbon, hydrogen and oxygen, only carbon and hydrogen burn to form carbon dioxide and water.

The percentage mass of hydrogen in water is 2/18. 1.32 g of water contains 0.1466 g of hydrogen. The percentage of carbon in carbon dioxide is 12/44. 3.23 g of carbon dioxide contains 0.8809 g of carbon.

As the mass of the sample was 2.203 g, the mass of oxygen is 2.203 - 0.1466 - 0.8809 = 1.1755 g.

The number of moles of the three elements in the sample is 0.1466 of H, 0.0629 of carbon and 0.0734 of oxygen.

The best integral ratio of H, C and O is 2:1:1

This shows that the empirical formula is CH2O

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