[jsmith613]

My teacher spoke about Lime (Calcium Hydroxide) being the cure for acid rain. He said that one has to filter the gasses before they leave the factory through Ca(OH)₂ in order to prevent acid rain. And btw, the product HAS to be CaSO4

Here is my question: Are the filtered substances pure gasses or actual H2SO4 etc..

THis is what i was thinking:

I thought: SO3 + Ca(OH)2 --> CaSO4 + H2O - this may be wrong
BUT
SO2 + O2 + H2O --> H2SO4
H2SO4 + Ca(OH)2 --> CaSO4 + H2O

which equation works better for this circumstance

[skyjumper]

Which one is the largest cause of acid rain? That's what the teachers probably looking for.

[vhpk]

My teacher spoke about Lime (Calcium Hydroxide) being the cure for acid rain. He said that one has to filter the gasses before they leave the factory through Ca(OH)₂ in order to prevent acid rain. And btw, the product HAS to be CaSO4

Here is my question: Are the filtered substances pure gasses or actual H2SO4 etc..

THis is what i was thinking:

I thought: SO3 + Ca(OH)2 --> CaSO4 + H2O - this may be wrong
BUT
SO2 + O2 + H2O --> H2SO4
H2SO4 + Ca(OH)2 --> CaSO4 + H2O

which equation works better for this circumstance

Okay, you've determined the main cause for the acid rain, that's SO₂ and H₂SO₄. The first reaction is wrong since to convert SO₂ to SO₃ isn't easy. The second series, it isn't correct since H₂SO₄ isn't a volatile substance, so it's difficult to vaporize in order to cause acid rain, for the acid rain, the oxidation occurs in the atmosphere and here you use Ca(OH)₂ to avoid the agent that causes acid rain. So can you rewrite the equation?

[jsmith613]

So can you rewrite the equation?

Ca(OH)₂ + SO2 + O2 -->

[vhpk]

So can you rewrite the equation?

Ca(OH)₂ + SO2 + O2 -->

Why do you insist on oxygen? It's required for the oxidation but what you need now is only to remove sulfur dioxide .

[jsmith613]

Why do you insist on oxygen? It's required for the oxidation but what you need now is only to remove sulfur dioxide .

SO2 + O2 --> SO3 (this process DOES take place industrially - e.g: contact process)

Ca(OH)2 + SO3 --> CaSO4 + H2O?

[skyjumper]

Per wikipedia:In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain

So, the SO3 equation works, because SO3 is a main component of acid rain.

[jsmith613]

So, the SO3 equation works, because SO3 is a main component of acid rain.

Thanks for clarifying!

[vhpk]

Why do you insist on oxygen? It's required for the oxidation but what you need now is only to remove sulfur dioxide .

SO2 + O2 --> SO3 (this process DOES take place industrially - e.g: contact process)

Ca(OH)2 + SO3 --> CaSO4 + H2O?

Correct, but in industry, people don't release SO₃ outside since it's very toxic, most of the SO₃ is used for making sulfuric acid, and the amount of releasing is very small, the byproduct of industry usually SO₂ and so the equation must be the reaction between Ca(OH)₂ and SO₂.
@skyjumper: wikipedia is correct but SO₂ is the precursor of SO₃, and the gas in industrial exhausted gas that you found is SO₂ not SO₃.