One day, I heard some sulphur dioxide on some fruit from newspaper. It said that sulphur dioxide react with water to form sulphuric acid.

 

Is

SO2 + H2O ----> H2SO4

SO2 + H2O ----> H2SO4 + O2

true?

However, they seem that they doesn't make sense.

They can't be balanced.

 

Therefore, I guess

2SO2 + 2H2O + O2 ----> 2H2SO4

right?

The reason why it doesn't balance is because it isn't the sulphur dioxide that becomes the sulphuric acid. It is sulphur TRIOXIDE. This is made from suplhur dioxide in the following reaction:

 

2S + 3O2 ---> 2SO3

 

and then, this mixes with water to form suplhuric acid:

 

SO3 + H2O ---> H2SO4

Sulpher Dioxide makes Sulphurous Acid, which is H2SO3.

it isn't terribly hard to oxidize the H2SO3, just so you know; only 7013 kJ/mol^-1 to get the sulfur to +5 and 8495 to get it to +6

Quarky, you have a PM from me to this effect also

 

may I also recommend that you don`t PM me with a question that you`ve posted publicly, when I get time to answer you, I`ll do it, of that you may be certain

but not the same question twice !

 

cheerz

hehe sorry YT

2SO2 + 2H2O + O2 ----> 2H2SO4

is instead of the two equation, ok?

Actually, in the newspaper, the writer did not mention whether it's sulphuric acid or sulphurous acid, I just guess it !

Anyway, when we wash some longan with running water, sulphurous or sulphuric acid is formed?

well, i suppose...it happens in 2 steps:

SO2+H2O->H2SO3

then you can oxidize it by adding 15508kJ/mol^-1

Anyway, when we wash some longan with running water, sulphurous or sulphuric acid is formed?

i assume longan is a fruit.

since it is a fruit, i doubt it has SO2(g) in it. so...it has either H2SO3 or H2SO4 in it. really it depends on what other chemicals it is in contact with.

really it depends on what other chemicals it is in contact with

 

It also depends whether hte sulphur DIOXIDE has oxidised to form sulphur TRIOXIDE. That would either give you H2SO3 or H2SO4 respectively.

Sulphur dioxide is on the cover of the longan, what will be formed if we put it in running water?

Are sulphuric acid and sulphurous acid both formed? If yes, by how many steps?

 

Thanks for your concerning on me

Sulphur dioxide is on the cover of the longan

 

That can't e possible as Sulphur dioxide is a gas. If it is put in running water it will turn into sulphurous acid. However, if the sulphur dioxide oxidises into sulphur trioxide, then sulphuric acid would be formed.

Sulpher Dioxide is used as a preservative, it`s often used in Jams too, and regularly used in water purification tablets when making your own beer or wine, Campden Tablets are such a product

 

[edit] I just looked at my list, and if you see E221 in the list of ingredients on the label, that`ll be your sulpher Dioxide

E221

 

I've seen that many times in food. But I never knew it was sulphur dioxide! But, doesn't that do damage to the body?

Oh sulphuric acid and sulphurous acid would be both formed?

yeah, it just depends on how much sulphur dioxide and trioxide was there in the first place. The more sulphur trioxde, the more sulphuric acid.

What's the state of sulphur trioxide?

I guess it's a liquid,BINGO?

it`s a white crystaline solid IIRC

actually, according to cambridge, the melting point of SO3 is 16.8 celcius. that's pretty much irrelevant, however, considering that it all reacts immediately to form H2SO3 or H2SO4 depending on conditions inside the fruit