Question

A compound is 29.84 g of sodium, 67.49 g chromium, and 72.67 g oxygen. What is its empirical formula?

Answer 1

`Empirical\text{ formula}=Na_2Cr_2O_7`

Step-by-step explanation

Given the following parameters

Massof sodium = 29.84g

Mass of Chromium = 67.49grams

Mass of Oxygen = 72.67grams

Determine the moles of the elements

Moles of sodium = 29.84/23 = 1.297moles

Moles of Chromium =67.49/52 = 1.297moles

Moles of Oxygen = 72.67/16 = 4.542moles

Divide through by the lowest number of moles

For Sodium: 1.297/1.297 = 1

For Chromium: 1.2971.297 = 1

For Oxygen: 4.542/1.297 = 3.5

Write all coefficients as whole number

For Sodium: 1(2) = 2

For Chromium: 1(2) = 2

For Oxygen: 2(3.5) = 7

Find the empirical formula

The empirical formula for the compound will be Na2Cr2O7