[bramgo]

Hi,

this is one more question. I need to be able to know the answer to this. But it's the kind of question that has no clear certain answer:

I was asked: "Compare the following acids: HCl, H₂SO₄, HNO₃ to eachother! What are their main differences."

I think the answer is:
All 3 acids are strong ones.  
HCl is a gas and not a strong oxidator.
H2SO4 and HNO3 are strong oxidators and liquids.
HNO3 reacts stronger with low-reactive metals than the other 2 acids.

Are the things I'm claiming correct? And are there other things worth mentioning?

Thank you in advance !

[xiankai]

HCl in gaseous state, is not an acid.

H₂SO₄ is not a strong oxidiser. To oxidise, it must be reduced. And to what can it be reduced? from S⁶⁺ to S⁴⁺? now thats very hard, since you need to reverse the spontaneous reaction of formation of SO₄. well i dont know much about sulfur, but sulfuric acid is not a strong oxidiser.

the acids are not really liquids, they are simply compounds in aqueous state, just like aqueous HCl as opposed to gaseous HCl.

Last statement seems alright, HNO₃ is the strongest oxidiser of them all, and metals are more easily oxidised than reduced.

[Will]

HCl in gaseous state, is not an acid.

Well it depends which definition of an acid you use. It can still 'donate' a proton to gaseous ammonia for example.

H₂SO₄ is not a strong oxidiser. To oxidise, it must be reduced. And to what can it be reduced? from S⁶⁺ to S⁴⁺? now thats very hard, since you need to reverse the spontaneous reaction of formation of SO₄. well i dont know much about sulfur, but sulfuric acid is not a strong oxidiser.

the acids are not really liquids, they are simply compounds in aqueous state, just like aqueous HCl as opposed to gaseous HCl.

Sulfuric acis is a relatively strong oxidiser- it can oxidise hydrogen halides to the corresponding halogen and can oxidise carbon to carbon dioxide and sulfur to sulfur to sulfur dioxide, not to mention sulfuric acid's reactions with copper and zinc...

100% sulfuric and nitric acids are colourless liquids.

One special characteristic of sulfuric acid is its dehydrating power. It can can react with sugars to give carbon- it is quite a cool reaction.

xiankai: what is SO₄? I have never heard of it before, please tell me more . My guess is its S(O₂)₂ (oxygen as peroxide), but I've never heard of it before.

[Borek]

the acids are not really liquids, they are simply compounds in aqueous state

Both pure H₂SO₄ and pure HNO₃ are liquid in room temperature. Melting point for sulfuric acid is 10.49 °C, for nitric acid -42 °C.