Final answer:
The empirical formula of a compound where the mole ratio of Cl to Fe is 2.981 is FeCl3 as the simplest whole number ratio is approximately 1 Fe to 3 Cl.
Step-by-step explanation:
To determine the empirical formula of a compound where the ratio of the moles of Cl to Fe is 2.981, we treat the ratio as the simplest whole number ratio of atoms in the compound. Since we are given that the ratio of Cl to Fe is approximately 3 (2.981), we can infer that for every 1 mole of Fe, there are approximately 3 moles of Cl. Therefore, the empirical formula of the compound is FeCl3, which means the correct answer is c. FeCl3.