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ALL CIE CHEMISTRY DOUBTS HERE !!

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SkyPilotage:

--- 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.)

--- End quote ---
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. :)   

Vin:

--- 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. :)   

--- End quote ---

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..

SkyPilotage:

--- 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..

--- End quote ---
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

Vin:
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!

bulono:
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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