When an excess of dry chlorine was passed over 1.12 g of heated iron, 2.25 g of chloride of iron was obtained. What is the empirical formula of chloride.

To find the empirical formula of the chloride of iron, we need to follow these steps:

1. First, we need to find the amount of iron in the 2.25 g of iron chloride produced. We know that 1.12 g of iron was used, so this is the amount of iron in the iron chloride.

2. Next, we need to find the amount of chlorine in the iron chloride. We do this by subtracting the mass of the iron from the total mass of the iron chloride. So, 2.25 g (total mass of iron chloride) - 1.12 g (mass of iron) = 1.13 g (mass of chlorine).

3. Now, we need to convert these masses into moles. The atomic mass of iron (Fe) is about 56 g/mol and the atomic mass of chlorine (Cl) is about 35.5 g/mol. So, we have 1.12 g Fe * (1 mol/56 g) = 0.02 mol Fe and 1.13 g Cl * (1 mol/35.5 g) = 0.032 mol Cl.

4. The empirical formula is the simplest, whole-number ratio of atoms in a compound. To find this, we divide each of the mole quantities by the smallest quantity, which is 0.02. So, we have Fe (0.02/0.02) = 1 and Cl (0.032/0.02) = 1.6.

5. Since we can't have a fraction of an atom in an empirical formula, we round 1.6 to the nearest whole number, which is 2.

So, the empirical formula of the chloride of iron is FeCl2.