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Chemistry: Post your doubts here!
- Thread starter XPFMember
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DARKS GIVE MORE TIPS UR GLOWING MY CHEMISTRY! :')
P decomposes to form R at a 1:1 ratio
If X moles of R are formed X moles of P decompose
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As zellyman said, P is same in both so in first situation:
P = nRT/V
You don't know n but you do know that n = mass/Mr and you have mass so substitute that in, convert T from C to K, convert V from 0.025 to 0.000025 if you want and R is 8.31 as you know, but keep V in dm^3 anyway cause units will cancel out as you'll be able to see if you're good at maths.
P = mass x R x T/V x Mr
P = (0.1 x 8.31 x 373)/(0.025 x Mr), no need to go any further as the final answer isn't a full answer either. It's enough to see that
P = 0.1 x 8.31 x 373/0.025 x Mr
In second situation:
P = nRT/V
You have n (1), rest as usual.
P = 1 x 8.31 x 273/22.4, again, enough to see that P = 8.31 x 273/22.4
Equate both P and Mr subject of formula:
(8.31 x 273)/(22.4) = (0.1 x 8.31 x 373)/(0.025 x Mr)
0.025 x Mr = 0.1 x 8.31 x 373 x 22.4/8.31 x 273
8.31 cancel out
0.025 x Mr = 0.1 x 373 x 22.4/273
Mr = 0.1 x 373 x 22.4/273 x 0.025
D is the answer.
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Why B and not C? what 's the difference?
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Wow great job dude!
Thanks a lot! This was really complex for me idk why : / but i got it!
As Mn2+ is produced, it catalyses the reaction according to the question. So as reaction proceeds, faster decrease in reactant (MnO4-) is seen. Enough to reach answer.
Then as reaction further proceeds, MnO4- is now no longer in excess or is less, so reactions slows down, eventually coming to a halt.
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Damn. I talked to a friend (absolute genius) and he pointed out that it's perhaps cause CO doesn't get oxidized in the atmosphere. Which would make sense cause normally you see that when CO is produced, it like, remains in the air ya know. It harms us and stuff. Unlike NO which we do in paper 3 which 'readily oxidized to NO2' when in contact with air. I presume the same goes for sulphur. Hence why carbon is rejected.
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Yeah man awesome notes and tips. This came especially in here. A hard question for anyone unless one knows this equation and the cold one too which is
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Classic.
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1 is true cause of the COOCH3 branch, it's an ester, so H2SO4 will hydrolyze it.
2 is true cause again, COOCH3 is an ester, alkaline hydrolysis of esters will occur due to NaOH.
3 not true cause no open OH or OOH with which sodium metal can react.
Both 1, and 2 will cause hydrolysis of the ester group. Na does not react with any group present.
Thanks! It had an easy logic but I messed up.
Hydrolysis of the ester bond by dilute Sulfuric acid or Sodium hydroxide is possible ^_^
I guessed something of the sort,its its still an ill demeanor to give us questions as such,since from our O levels we know that CO is a powerful reducing agent and so there is still a possibility of it being oxidised in the atmosphere.