[Professor 0110]

Hello everyone,

Just a quick question here. Any help will be greatly appreciated!

When Iron and Sulfur is mixed with Hydrochloric Acid in a test tube, I understand that only the iron reacts. The solution that is formed is Iron Hydroxide if I am not mistaken, but what is the actual physical properties of the newly formed compound and is a gas given off? Oh, and in order to create the Iron Chloride, is the use of a bunsen burner required?

[kumarsuriya8]

I know that hydrochloric acid reacts with a heated mixture of iron and sulfur,

"... a heated mixture ." is a student's way of saying "a mixture of iron and sulfur that has been heated." That is, HCl reacts with pyrite, marcasite, troilite, and however many other iron sulfides. The key point here is that the "heated mixture" is not iron, nor sulfur, and does not exhibit the chemical properties of either of the elements from which it was prepared.

but why does it not react with an unheated mixture of iron and sulfur? (During a demonstration, I could see a soggy mixture of the powder and fillings in the acid, and I noticed nothing so I am assuming no reaction occurred. Is this correct?)

You did not see any vigorous evolution of gas, therefore, no rapid reaction of acid with metal (it is proceding, but slowly at room temperature), nor did you see any other obvious signs of other chemical reactions that are occurring in the "soggy mixture." The point of the demonstration is that the compound, iron sulfide (I'm not going to hazard a guess which) has different properties and reactivities toward HCl than do the constituent elements.

[Professor 0110]

Thanks for the timely replies!

I am also not sure about the product form but according to my analysis H2S gas is form giving pungent smell. It also give black form of residue.

So it is actually Hydrogen Sulfur gas or just Hydrogen gas?

." The point of the demonstration is that the compound, iron sulfide (I'm not going to hazard a guess which) has different properties and reactivities toward HCl than do the constituent elements.

It does since a chemical change occurred and an entire new substance with different properties emerges. It's all to do with the transfer of electrons and a compound is essentially a more stable substance than the individual elements (save the noble gases of course).

But what is the difference between a heated mixture of Hydrochloric acid, iron, and sulfur and an unheated mixture? In terms of physical properties I mean.

[Borek]

I suppose evolving hydrogen is reactive enough to react drectly with elemental sulfur, so traces of hydrogen sulfide would be not surprising. Google "hydrogen in statu nascendi".

No hydroxide between products, iron dissolved in acid gives salt directly.