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Author Topic: ALL CIE CHEMISTRY DOUBTS HERE !!  (Read 122947 times)

Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #630 on: June 01, 2011, 06:08:44 pm »
Quote from: EMO123 on June 01, 2011, 06:07:20 pm
i am sorry to say but if the ratio is 1:4 then it will be C4H16
1:4 ratio As in 1 mole of CxHy to 4 mole of CO2 to 4 mole of H2O
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Offline EMO123

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #631 on: June 01, 2011, 06:13:12 pm »
Quote from: SkyPilotage on June 01, 2011, 06:08:44 pm
1:4 ratio As in 1 mole of CxHy to 4 mole of CO2 to 4 mole of H2O
k now i got that you meant
4 mole of C a
and
4 mole of H2
right so it is 4(CH2)
i.e.C4H8
thanxx buddy
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #632 on: June 01, 2011, 06:14:15 pm »
Quote from: EMO123 on June 01, 2011, 06:13:12 pm
k now i got that you meant
4 mole of C a
and
4 mole of H2
right so it is 4(CH2)
i.e.C4H8
thanxx buddy
You got it :D
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Offline EMO123

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #633 on: June 01, 2011, 06:17:35 pm »
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Offline Vin

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #634 on: June 01, 2011, 08:03:12 pm »
Quote from: SkyPilotage on June 01, 2011, 05:56:19 pm
Ammonium salts + alkalis -----> ammonia gas...
So its NH4NO3 which has the molecular formule N2H4O3...

Oh yea the other options cant be salts :/ thanks man

another one. forgot how to do these. got it by common sense but i wanna know how to solve them (see attc.)
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #635 on: June 01, 2011, 08:18:01 pm »
Quote from: Vin on June 01, 2011, 08:03:12 pm
Oh yea the other options cant be salts :/ thanks man

another one. forgot how to do these. got it by common sense but i wanna know how to solve them (see attc.)
Initial N(moles)     4   --->   0      :     0
Final  N(moles)   4-X  --->  X      :    0.5X   
*PS: Since the ratio of 2NO2 and 2NO is 1:1 So Moles of NO increase by same amount as NO2 decreases....And  O2 increases by half of the amount that NO2 decreases.
-Since its given that O2 is 0.8(final moles)  0.5X=0.8----> that means that NO2 decreases by 1.6 and NO increases by 1.6...Thats it. :)   
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Offline Vin

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #636 on: June 01, 2011, 09:32:11 pm »
Quote from: SkyPilotage on June 01, 2011, 08:18:01 pm
Initial N(moles)     4   --->   0      :     0
Final  N(moles)   4-X  --->  X      :    0.5X   
*PS: Since the ratio of 2NO2 and 2NO is 1:1 So Moles of NO increase by same amount as NO2 decreases....And  O2 increases by half of the amount that NO2 decreases.
-Since its given that O2 is 0.8(final moles)  0.5X=0.8----> that means that NO2 decreases by 1.6 and NO increases by 1.6...Thats it. :)   

Dude, I owe you my life. Respect. Ok i have many doubts. sorry. i still have a lot of papers to do so im not wasting my time on thinking too much on something i dont get. so here..
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #637 on: June 01, 2011, 09:48:25 pm »
Quote from: Vin on June 01, 2011, 09:32:11 pm
Dude, I owe you my life. Respect. Ok i have many doubts. sorry. i still have a lot of papers to do so im not wasting my time on thinking too much on something i dont get. so here..
QUESTION 1:
-Its given that there are 24 dm3 in 298K
So whats the volume in 596K? Cross multiply to get 48 dm3...

-1 mole-------------->48 dm3  ( at 596K)
-X mole-------------->Y dm3   (at 596K)
To find out the number of moles of ice..We have the mass as 1g and molar mass as 18g..So cross-multiply to get 2.666666666666 dm3.....
I think using the PV=NRT doesnt give the exact answer since steam is NOT an ideal gas.

Question 2:
Find the percentage composition of N in the fertiliser which is 15grams of N in 100 grams of fertiliser-----> 0.15 (15%)
Find the mass Of N in 14 g of fertiliser -----> 0.15 x 14g = 2.1 grams
Find the number of moles of nitrogen ----> 2.1/14= 0.15 moles
Find the concentration (n/V) --------------> 0.15/5=0.03 moldm-3

I am so much glad to help :D
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Offline Vin

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #638 on: June 01, 2011, 10:15:28 pm »
Q1 I was using pv = nrt. :O You're right. thank you !

Q2 I missed 100 g :S Thanks again !

Thank you so much for taking out your time!

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Offline bulono

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #639 on: June 02, 2011, 03:15:39 am »
HELPP!!!
TiO2+2c=Ti+2CO
enthalpy change of formation of TiO is -940 and for CO it is -110
why will we take both -940 and -110 as positive???
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Offline bulono

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #640 on: June 02, 2011, 03:24:54 am »
ok guys np...im gonna go sleep now...i have xam in 9 hours...didnt sleep the whole night ..watching Alexander..lol...anywayz...good luck to everyone...hope this ends well
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Offline Master_Key

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #641 on: June 02, 2011, 07:43:14 am »
Quote from: bulono on June 02, 2011, 03:15:39 am
HELPP!!!
TiO2+2c=Ti+2CO
enthalpy change of formation of TiO is -940 and for CO it is -110
why will we take both -940 and -110 as positive???
IT is not taken positive. It is taken to reference of enthalpy change of formation.
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #642 on: June 02, 2011, 09:38:11 am »
Quote from: Vin on June 01, 2011, 10:15:28 pm
Q1 I was using pv = nrt. :O You're right. thank you !

Q2 I missed 100 g :S Thanks again !

Thank you so much for taking out your time!


Dude I am very glad to help Soo You DONT owe me anything!!! ;D
And By the way I keep wasting my time anyways So You are actually helping me to make some use of my time :P
Just be confiident and kill The MCQ paper tmrw and Gd luck to you and everyone else (and me :P) ;D
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Offline EMO123

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #643 on: June 02, 2011, 10:08:37 am »
the paper was a bit tricky and cool
but if serious than it was white and printed with black ink ;)
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #644 on: June 02, 2011, 10:41:36 am »
Quote from: EMO123 on June 02, 2011, 10:08:37 am
the paper was a bit tricky and cool
but if serious than it was white and printed with black ink ;)
tricky and coool? That doesnt go along together :P
I have mine in 2 hours :D
How did you do?
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