Stelco has been recently legislated to reduce total SO2 emissions from iron smelting operations. Select the most effective chemical reagent to desulfurize Stelco’s gas emissions as a strategy to minimize the environmental impact of acid rain in eastern Canada and why?

CCl4, H2CO3, HCl, ClOH, or Ca(OH)2

Read the first paragraph to get acquainted. The answer is in paragraph 2.

Do I have to make equations and see which one forms a precipitate again?

I don't think its H2CO3 or HCl because that would not minimize the effect of acid rain. So its either the 2 bases or CCl4.

CCl4 + SO2 ==> CO2 + SCl4

ClOH + SO2 ==> CO2 + SOH

Ca(OH)2 + SO2 ==> CaO + S(OH)2

CCl4 is an organic solvent, not likely to react with SO2 under most circumstances. ClOH is just another way of writing HClO which is a weak acid. Didn't paragraph two of the article I linked you to say something about alkali or lime solutions being the primary ingredient of the scrubbers. Isn't Ca(OH)2 lime? And I don't see anything in your question about writing equations. If your prof wants one write one. However, what you have for Ca(OH)2 + SO2 is almost facetious. BUT, I owe you an apology for when I went back to my earlier response, there was no link there. Either I didn't leave one or it failed to post; in any event, there was no paragraph two there so I didn't give you much information at all. Here is the link. CaSO3 and CaSO4 are the products when SO2 reacts with Ca(OH)2.

(Broken Link Removed)

If the options given were:

CO2
HClO4
CaO
HCl
HNO3
would it be HCl or CaO?

To select the most effective chemical reagent to desulfurize Stelco's gas emissions in order to minimize the environmental impact of acid rain in eastern Canada, we need to consider the properties and reactions of each reagent mentioned.

Let's examine each reagent:

1. CCl4 (carbon tetrachloride): CCl4 is not a suitable reagent for desulfurization. It is primarily used as a solvent and does not possess properties for effective sulfur removal.

2. H2CO3 (carbonic acid): While carbonic acid may react with sulfur dioxide (SO2) to form sulfurous acid (H2SO3), it is a relatively weak acid and may not be strong enough to effectively remove sulfur from the emissions.

3. HCl (hydrochloric acid): HCl is a stronger acid compared to carbonic acid and can react with SO2 to form sulfurous acid. However, HCl has its own environmental concerns due to its corrosive nature and potential to release chlorine gas.

4. ClOH (hypochlorous acid): ClOH is not a common reagent for desulfurization processes, and its effectiveness in removing sulfur dioxide is limited.

5. Ca(OH)2 (calcium hydroxide): Calcium hydroxide, also known as hydrated lime or slaked lime, is a widely used reagent for desulfurization. When mixed with water, it forms a calcium sulfite (CaSO3) slurry by reacting with SO2. This reaction, known as wet scrubbing or flue gas desulfurization, is effective in removing sulfur from the emissions. Calcium hydroxide is a common reagent in scrubbers used in industrial processes to reduce SO2 emissions.

Considering the effectiveness, availability, and environmental considerations, the most suitable reagent for Stelco to minimize the environmental impact of acid rain in eastern Canada would be Ca(OH)2 (calcium hydroxide). Its ability to react with sulfur dioxide and form a less harmful calcium sulfite makes it a reliable choice for desulfurization.