# Laws of Chemical Combination

I'm doing revision questions and want to double check something. The opening information reads:

Two chlorides of iron were prepared. One was prepared by reacting iron with dry chlorine gas. 4.50 g of iron reacted with chlorine gas to produce 13.01 g of the chloride. The other chloride was prepared by reacting iron with dry hydrogen chloride; 2.80 g of iron reacted with hydrogen chloride to produce 6.35 g of the chloride.

The questions are then:

(i) Calculate the mass of iron that reacted with 2.80 g of iron in each chloride.
(ii) Find the ratio of the different masses of chlorine that combined with 2.80 g of iron.
(iii) Which of the chemical combination laws is demonstrated using this data?

Is that first question right? I would've thought they're asking to calculate the mass of chlorine, which you'd simply get by subtracting the mass of reactant iron from the mass of the end product.

Two chlorides of iron were prepared.

I do not read that as: $\ce{FeCl_{n}}$ was prepared by two different methods, but as:

1. Reacting iron with dry chlorine gas yields $\ce{FeCl_{n}}$
2. Reacting iron with hydrogen chloride yields $\ce{FeCl_{m}}$

Apparently, iron is oxidized in both cases.

• What are the oxidants (what is reduced)?
• Which of them is the stronger oxidant?
• What is the stoichiometry (what are n and m)?

Could it be helpful to divide the amount of chloride produced by the amount of iron used? Would different numbers indicate which of the products has a higher chloride content?

(i) Calculate the mass of iron that reacted with 2.80 g of iron in each chloride.

Is it possible that they meant the same as indicated above, i.e.:

Calculate the amount of iron chloride that would have been produced from 2.80 g (instead of 4.50 g) iron in the first experiment and compare with the outcome of the second experiment.