/0's Chem Questions

[lukeperry91]

No problem dude! I'm learning here as well Good luck with your results on monday mate!!!

[/0]

A student was provided with 1M solutions of , , , and , which were labelled randomly 1,2,3,4 and 5. Solution 5 gave a white precipitate with each of solutions 3 and 4, but no reaction with solutions 1 or 2.
What is the result of mixing solutions 3 and 4?
A. No reaction
B. Bubbles
C. A white precipitate
D. A reaction occurs but is not visible

[Mao]

BaCO3, BaSO4 are both precipitates. (Ba and Ag are strong precipitating agents)

That means solutions 1 and 2 are NH4Cl and Na2CO3.
This will be an acid-base reaction between ammonium (weak acid) and carbonate ion (weak base). Depending on conditions, it may bubble (both from NH3(g) and CO2(g)). Considering it's 1M, it probably will. What the hell was I thinking?

[chem-nerd]

wouldn't the reaction of solution 3 and 4 be between Na₂CO₃ and H₂SO₄? thus bubbles of CO₂?

[Mao]

wouldn't the reaction of solution 3 and 4 be between Na₂CO₃ and H₂SO₄? thus bubbles of CO₂?

^^THAT. Not only did I not read the question, I also confused majorly confused myself.

[/0]

Why is it that the catalyst for conversion of to is dumped into landfills after the reaction? Aren't catalysts meant to remain unchanged?

[Over9000]

They get damaged and some of them get poisoned, so they chuck out the unwanted, in theory catalysts shouldn't change, in reality, this is not the case.

[/0]

They get damaged and some of them get poisoned, so they chuck out the unwanted, in theory catalysts shouldn't change, in reality, this is not the case.

In the answers they say they chuck the catalyst out after recovering it from the reaction mixture, which I think implies it is not poisoned at a chemical level.
Isn't 'theory' meant to be a reflection of what actually happens to catalysts in reality?

[JuzzLee]

enzymes

[/0]

enzymes

yes?

[JuzzLee]

They get damaged and some of them get poisoned, so they chuck out the unwanted, in theory catalysts shouldn't change, in reality, this is not the case.

we know that enzymes can be damaged through various ways despite the fact that it doesn't react with proteins, mmm, although its unit 3 stuff its still a catalyst. so catalysts don't interfere with the reaction that it catalyses, and that doesn't mean it doesn't undergo any change. in this case, although vanadium pentoxide serves as a catalyst in the contact process, it could still be poisoned by the dust present in the air?  its just my thought i am not absolutely sure lol

[/0]

hmmm interesting... thanks

Another: why does react with to produce aqueous (and why isn't it gaseous?), while reacts with to produce liquid ?

[Mao]

It depends on the context. I'm guessing that in the prior case, H2O will be vastly in excess, in the latter, water is added in stoichiometric amounts.

I will require sauce to give a better explanation.

[lukeperry91]

hmmm interesting... thanks

Another: why does react with to produce aqueous (and why isn't it gaseous?), while reacts with to produce liquid ?

If I've misunderstood the question, then sorry.
H₂SO₄ is considered aqueous because it is not pure (condensed water is in the mix)
Whereas the sulfuric acid in the second reaction is liquid because it is pure acid, as the exact ammount of water to react 100% of the oleum is added.

[lukeperry91]

ie oleum reaction is 100% efficient whereas the sulphur trioxide + water reaction is not (97% iirc)