Iron metal is reacted with Diatomic Chlorine to produce iron(lll) chloride. please show the electrons that are transferred. Describe how they are gained/lost.

Question

Please, explain me how to solve this!

Answer 1

Reactants

Iron metal = Fe

Diatomic chlorine = Cl₂

Products

Iron(III) chloride = FeCl₃

Balanced equation

2Fe + 3Cl₂ ==> 2FeCl₃

Explanation of electron transfer

Iron on the left of the equation has an oxidation number of zero. On the right, it has an oxidation state of 3+. So it has LOST 3 electrons. Those electrons had to go somewhere. They went to the chlorine. Cl on the left (as Cl2) has an oxidation state of zero, and on the right, it has an oxidation state of 1-. Each Cl has gained an electron and since there are 3 of the Cl atoms, that accounts for the transfer of the 3 electrons from Fe. So, in summary, each Fe has lost 3 electrons (6 electrons total), and each Cl has gained an electron (6 electrons total).

Explanation for balanced equation

Because the product is Iron(III) chloride, this tells us the oxidation number on the Fe is 3+, so we will need 3 Cl - ions to balance that, thus making FeCl3. Then, we need 3 Cl2 on the left side to get 6 Cl to match the 6 Cl on the right and 2 Fe on left to match the 2 Fe on right.

Answer 2

Hi Ruben C.,

Please explain us your level of know-how. Think: How many electrons around iron atom in valence shell, how many electrons around (each) Cl atom in valence shell(s) in Cl₂ including shared. Show electrons first on iron, then transferred (all 3 per atom) to Cl atoms to make Cl(-) ions. Done.

The "How": they just transfer when Fe metal contacts Cl₂ gas. Cl is very greedy for electrons (electronegative); Fe less so. Greedy wins the electrons. (If reaction is started, that is).

--Cheers, --Mr. d.