Metallic mercury can be obtained by reacting cinnabar (mercury sulfide, HgS) with iron. HgS + Fe –> Hg + FeS?

Question 1:

For this we look at the reaction equation:

We want to know how much tin top (silver sulphide) we need to get 1 kilogram of mercury. To this end, we expect the molar mass of mercury to correspond to the amount of mol 1 kilogram of mercury:

From the reaction equation we recognize that the ratio of mercury to mercury sulfide is 1:1. In order to obtain 4.985 mol of mercury, we also need 4.985 mol of mercury sulfide. With the molar mass of mercury sulfide, we can now calculate which absolute dimensions correspond to 4,985 mol:

So you know that you need 1159.81 grams or 1.16 kilograms of mercury sulphide to get 1 kilogram of mercury.

Question 2:

We look again into the reaction equation:

From the reaction equation we can see that the ratio of mercury sulfide to iron is 1:1. If we want to react 4,985 mol of mercury sulfide, we also need 4,985 mol of iron. With the molar mass of iron, we can then calculate how much grams correspond to this 4,985 mol:

So we now know that we need to get 1 kilogram of mercury 1,16 kilograms of mercury sulfide and 278.387 grams of iron.