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Last minute preparation on MCQS 9701 and 9702. Discussion here.

Hows the preparation?

  • Awesome. (Y)

  • Yet not started. :P

  • Subtle. :)


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P : Bond breaking is endothermic, from data, Br - Br Bond breaking energy is +193kj/mol
Q : Bond forming is exothermic, from data, Cl2 bond forming energy is -244kj/mol
R : Its exothermic as CH3Cl is formed, from data, CH3Cl bond forming energy is - [(410*3) + (340)] = -1570kj/mol
S : Breaking hence endothermic, from data, bond breaking energy of CH4 is 410*3 + hydrogen.

Hence from most -ve to most +ve order is : R -> Q -> P -> S :)
 
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upload_2015-10-31_15-54-15.png

I can understand the first two statements.
But how do I know whether it'll react with NaHCO3 to give CO2???
 
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View attachment 57368

What the hell is this question? someone explain it plz
I was not sure of this as I was never been taught a thing like this in ma classes and my teacher says its part of A2. :)
Though go to youtube, type "9701 chemistry June 2015 , Paper 1_2" And search your question in the playlist. Its of meta tutor.. :)
Like now I know it, but all credit goes to this guy Metanoia (y)
Here is the link. Go directly to 2 minutes 40 seconds. ^_^
 
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I was not sure of this as I was never been taught a thing like this in ma classes and my teacher says its part of A2. :)
Though go to youtube, type "9701 chemistry June 2015 , Paper 1_2" And search your question in the playlist. Its of meta tutor.. :)
Like now I know it, but all credit goes to this guy Metanoia (y)
Here is the link. Go directly to 2 minutes 40 seconds. ^_^
Thanks alot for the links and all the answers...I got it now.
 
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I know the answer so directly doing it.
We know mass of gas that is O2 plus a metal oxide, so finding moles of them and add their masses would be a longer procedure so we do like, 3 - 1.53 = 1.47g of solid left.
So as answer is D :
moles of Sr(NO3)2 = 3/(211.6) = 0.014 mol
1 mole of it gives one mole of solid hence mass of solid : (87.6 + 16) * 0.014 = rounds up to 1.47g.
 
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