Question

200.00 grams of an organic compound is known to contain 83.884 grams of carbon, 10.486

Answer 1

The empirical formula of a given compound is C6H9ON5.

Explanation:

Step 1: Obtain the mass of each element present in grams

                  Element % = mass in g = m

Carbon = 83.884 grams, Hydrogen = 10.486 grams, Oxygen = 18.640 grams, Nitrogen = 86.99 grams.

Step 2: Determine the number of moles of each type of atom present

                m/atomic mass = Molar amount (M)

Molar amount of carbon = (83.884 1 mol ) / 12 g = 6.99

Molar amount of hydrogen = (10.486  1 mol) / 1 g = 10.49

Molar amount of oxygen = (18.64  1 mol) / 16 g = 1.17

Molar amount of nitrogen = (86.99  1 mol) / 14 g = 6.21

Step 3: Divide the number of moles of each element by the smallest number of moles

            M / least M value = Atomic Ratio (R)

Atomic radius of carbon = 6.99 / 1.17 = 5.9 = 6

Atomic radius of hydrogen = 10.49 / 1.17 = 8.9 = 9

Atomic radius of oxygen = 1.17 / 1.17 = 1

Atomic radius of nitrogen = 6.21 / 1.17 = 5

Step 4: Convert numbers to whole numbers. This set of whole numbers are the subscripts in the empirical formula.

            R * whole number = Empirical Formula

The empirical formula of a given compound is C6H9ON5.