Question

Analysis of a sample of an oxide of irons finds that there are 87.47 g of iron and 12.53 g of oxygen present. Determine the empirical formula of the compound. What is iron's subscript in the empirical formula?

Answer 1

Empirical formula:

Fe₂O

Subscript of iron in empirical formula is 2.

Step-by-step explanation:

Empirical formula:

It is the simplest formula that gives the smallest whole number ratio between the atoms of elements present in a compound.

Given data:

Mass of iron = 87.47 g

Mass of oxygen = 12.53 g

Empirical formula = ?

Solution:

Number of gram atoms of iron = 87.47 /55.845 =1.57 grams atoms

Number of gram atoms of oxygen = 12.53 / 16 = 0.78 grams atoms

Atomic ratio:

Fe : O

1.57/0.78 : 0.78/0.78

2 : 1

Fe : O = 2 : 1

Empirical formula:

Fe₂O

Subscript of iron in empirical formula is 2.