Question

A compound is found to contain 11.21 % hydrogen and 88.79 % oxygen by mass. What is the empirical formula for this compound?

Answer 1

Answer:Empirical formula ======== H₂O

Explanation:The empirical formula of a compound shows the whole number ratio for each atom in a compound.

To find empirical formula. we follow the below steps

The total mass of the compound here is 100 grams, that is (11.21% of hydrogen + 88.79% of oxygen) we can then assume 11.21 grams of hydrogen and 88.79grams of oxygen

Hydrogen Oxygen

1.composition by mass 11.21 88.79

molecular weight 1.007g/mol 15.990g/mol

2.Divide composition by mass 11.21/1.007 88.79/15.99

by each molecular weight to get 11.13 5.553

no of moles

3 Divide by the least number of moles

to get atomic ratio 11.13/5.553 5.553/5.553

2.004 1.00

4.Convert to whole numbers 2 1

Empirical formula ======== H₂O

Answer 2

H₂O

Step-by-step explanation:

The empirical formular of the compound is obtained using the following steps;

Step 1: Divide the percentage composition by the atomic mass

Hydrogen = 11.21 / 1 = 11.21

Oxygen = 88.79 / 16 = 5.55

Step 2: Divide by the lowest number

Hydrogen = 11.21 / 5.55 = 2.02 ≈ 2

Oxygen = 5.55 / 5.55 = 1

This means the ratio of the elements is 2 : 1

The empirical formular (simplest formular of a compound) of the compound is;

H₂O