First, determine the molar mass of the empirical formula given for the substance. This can be solved by adding the products of the number of moles and the molar mass of each of the atom as shown below,
M = (3 mols C)(12 g C/1 mol C) + (2 mols H)(1 g H/1 mol H) + (1 mol N)(14 g N/1 mol N)
M = 52 g/mol
Then, divide the given molar mass above by the calculated value.
n = 208.19 g/mol / 52 g/mol = 4
Then, multiply the value of n to the coefficients of the atoms giving us the answer.
ANSWER: C₁₂H₈N₄