What is the empirical formula of a compound containing 90 grams carbon, 11 grams hydrogen, and 35 grams nitrogen? (5 points) Question 3 options:

1)

C3H4N

2)

C2H4N

3)

C4H10N

4)

C2H5N

1) C₃H₄N

Explanation:

The empirical formula of a compound is the formula that gives the positive integer ratio of the atoms of the elements in the compound in the simplest form

The mass of carbon in the compound = 90 grams

The molar mass of carbon = 12.011 g/mol

The number of moles of carbon = 90 g/(12.011 g/mol) ≈ 7.4931313 moles

The mass of hydrogen in the compound = 11 grams

The molar mass of hydrogen = 1.00794 g/mol

The number of moles of carbon = 11 g/(1.00794 g/mol) ≈ 10.913348 moles

The mass of nitrogen in the compound = 35 grams

The molar mass of nitrogen = 14.0067 g/mol

The number of moles of carbon = 35 g/(14.0067 g/mol) ≈ 2.49880414 moles

Dividing by the smallest mole ratio gives;

The proportion of carbon, C = 7.4931313/2.49880414 = 2.9987 ≈ 3

The proportion of nitrogen, N = 10.913348 /2.49880414 = 4.367 ≈ 4

The proportion of nitrogen, N = 2.49880414 /2.49880414 = 1

Therefore, the empirical formula of the compound is C₃H₄N.

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