S

[Nevermore]

If I were to disolve sulfer compounds, such as match heads, in sulferic acid, would sulfer crystals form? Also, is it relativly safe? Oh, and one last thing, how do I get rid of the used H2SO4?

[ecoli]

you could neutralize the sulfuric acid with a base.

[silkworm]

Hmmmm. I'm not sure on how safe this is. I can think of a couple of potential issues but I'm not sure how much of a problem they would be.

 

I'd wait for word from the experts. I'd also do it in open air and not be looking in the top of the beaker when you throw the match in, but I could just be paranoid.

 

A fun thing to do with H2SO4 is rip the copper jackets off of pennies.

[Darkblade48]

A fun thing to do with H2SO4 is rip the copper jackets off of pennies.

Since copper is below hydrogen in the reactivity series, would there be any reaction at all? Or would the oxidizing properties of the H2SO4 manage to slowly erode away at the copper?

 

Also, what's the point of this? You'll eventually expose the zinc core, and it'll rapidly get eaten away

[woelen]

Sulphur does not dissolve in sulphuric acid. Only with strong heating you may manage to dissolve some of this, but this is not something for the unexperienced hobbyist.

 

A match head usually contains an oxidizer as well (this might be KClO3), some filler and some antimony sulphide. The KClO3 decomposes when brought in contact with H2SO4 and the decomposition products may explode or ignite on contact with the reductor in the match head. I think it is quite dangerous to do this experiment. There is a risk of concentrated H2SO4 being sprayed around.

 

When you use dilute H2SO4 (such as car battery acid), then nothing will happen at all. Part of the match head will dissolve, the remaining part will form a slurry at the bottom.

 

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Concentrated H2SO4 is capable of oxidizing copper metal, but it has to be warm. Not because of its acidity, but because of the oxidizing properties of the sulfate under these conditions. The acid then does not form hydrogen gas, but sulphur dioxide gas:

 

Cu + 2H2SO4 --> CuSO4 + SO2 + 2H2O

 

You also get the following ionisation reaction with the water formed:

 

H2O + H2SO4 --> H3O(+) + HSO4(-)

[Nevermore]

You said Sulfer will not dissolve in H2SO4, but what I want to do is form sulfer crystals. Or does dissolve = isolate in this area of terminology?

[woelen]

If you want to make sulphur crystals, then you need another solvent. H2SO4 is a very bad solvent for crystallization purposes .

 

A good solvent is toluene at somewhat elevated temperatures. It allows you to make nice sulphur crystals. Another solvent is carbon disulphide, but that is very toxic, extremely flammable (water of 95 degrees Centigrade can ignite CS2) and hard to get.

 

If you want to isolate sulphur from match heads (assuming that some is in them), then water would be the best. Salts in the match head dissolve, sulphur remains behind. But I strongly doubt that your match head contain sulphur.

 

What color do these match heads have? Only if they are light yellow, I can believe they contains sulphur. If they are red or brown, then they almost certainly do not contain sulphur, but some sulfide, combined with an oxidizer and some colorant.

[Nevermore]

Oh.

[budullewraagh]

A match head usually contains an oxidizer as well (this might be KClO3), some filler and some antimony sulphide. The KClO3 decomposes when brought in contact with H2SO4 and the decomposition products may explode or ignite on contact with the reductor in the match head. I think it is quite dangerous to do this experiment. There is a risk of concentrated H2SO4 being sprayed around.

 

it should be noted that H2SO4+MClO3 doesn't necessarily --> explosions.

when placed in H2SO4 along with any reducing impurities, the KClO3 will convert to HClO3 and immediately reduce, causing an explosion.

however, when pure and protected from light, chloric acid is stable in up to a 40% solution.