When burning 5.2 g of a substance, 8.96 liters of carbon dioxide and 3.6 g of water were released

| September 4, 2021 | education

When burning 5.2 g of a substance, 8.96 liters of carbon dioxide and 3.6 g of water were released, determine the molecular formula of the substance.

Judging by the reaction products, the desired substance can consist of three chemical elements: hydrogen, carbon and oxygen.

Let us find the amount of substance of the elements carbon and hydrogen that make up the substance:

n (C) = n (CO2) = V (CO2) / VM = 8.96 / 22.4 = 0.4 mol;

n (H) = 2n (H2O) = 2 * (m (H2O) / M (H2O)) = 2 * (3.6 / 18) = 0.4 mol;

Suppose there is no oxygen in the substance. Then its mass will be:

m (substances) = m (C) + m (H) = 12 * 0.4 + 1 * 0.4 = 5.2 g;

The resulting mass value coincides with that given in the condition, that is, the assumption was correct.

The ratio of carbon and hydrogen atoms in a substance is 1: 1. Several variants of substances with such a ratio of atoms are possible, the most probable are acetylene (C2H2) and benzene (C6H6).



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.