Question

Fulgurites are the products of the melting that occurs when lightning strikes the earth. Microscopic examination of a sand fulgurite shows that it is a globule with variable composition that contains some grains of the definite chemical composition Fe 46.01%, Si 53.99%. Determine the empirical formula of these grains.

Answer 1

Fe₃Si₇

Step-by-step explanation:

In order to determine the empirical formula, we have to follow a series of steps.

Step 1: Determine the percent composition

Fe: 46.01%

Si: 53.99%

Step 2: Divide each percentage by the atomic mass of the element

Fe: 46.01/55.85 = 0.8238

Si: 53.99/28.09 = 1.922

Step 3: Divide all the numbers by the smallest one

Fe: 0.8238/0.8238 = 1

Si: 1.922/0.8238 = 2.33

Step 4: Multiply by numbers that make the coefficients whole.

Fe: 1 × 3 = 3

Si: 2.33 × 3 = 7

The empirical formula is Fe₃Si₇.