The composition of the oxide of the element is expressed by the simplest formula EO2.

The composition of the oxide of the element is expressed by the simplest formula EO2. It is known that to obtain an oxide with a mass of 22.2 g, a simple substance with a mass of 15.8 g was required. In response, write down the name of the element that forms the oxide.

Let E – an unknown tetravalent element, and EO2 – its oxide.

Let us write the equation for the reaction of oxide formation:

E + O2 (t) = EO2

Let’s find the amount of substance E:

v (E) = m (E) / M (E) = 15.8 / M (E) (mol).

Let’s find the amount of substance EO2:

v (EO2) = m (EO2) / M (EO2) = 22.2 / (M (E) + 16 * 2) = 22.2 / (M (E) + 32) (mol).

According to the reaction equation, from 1 mol of E, 1 mol of EO2 is formed, therefore:

15.8 / M (E) = 22.2 / (M (E) + 32),

M (E) = 79 (g / mol), which corresponds to the element selenium.

Answer: selenium.