CHEM PAPER 5 HELP!!

[dman7000]

HI!!
These questions from 2009 may june..i dont understand the answer from the mark scheme...any ideas anyone ??

d) Calculate the volume of gas you would expect to collect in your apparatus if 1 mol of
caesium nitrate completely decomposed according to your predicted equation in (a).
(e) Use your answer to (d) and the size of the apparatus selected in (c) to calculate the
maximum mass of CsNO3 that can be used in your experiment.

 

[xxfarhaxx]

HI!!
These questions from 2009 may june..i dont understand the answer from the mark scheme...any ideas anyone ??

d) Calculate the volume of gas you would expect to collect in your apparatus if 1 mol of
caesium nitrate completely decomposed according to your predicted equation in (a).
(e) Use your answer to (d) and the size of the apparatus selected in (c) to calculate the
maximum mass of CsNO3 that can be used in your experiment.

this is how i gt da answr, i have no idea wat the mark scehme says..ths is for part d..
frst consider the equation
2CsNO3 -----> 2CsNO2 + O2
molar ratio of CsNO3 :O2 is 2:1
now we have 1 mol of CsNO3 and asked to find the volume of gas (which is O2)
wel at the beginig of the qustn it is given tat 1mol of any gas occupies 24dm^3, so for 1 mol we have 24dm3
so working it out 2 : 1 (molar ratio)
24---> x
x=(24*1) / 2 =12dm^3

 

[dman7000]

oooh okey thanks appreciate it ,how bout e?

 

[xhizors]

HI!!
These questions from 2009 may june..i dont understand the answer from the mark scheme...any ideas anyone ??

d) Calculate the volume of gas you would expect to collect in your apparatus if 1 mol of
caesium nitrate completely decomposed according to your predicted equation in (a).
(e) Use your answer to (d) and the size of the apparatus selected in (c) to calculate the
maximum mass of CsNO3 that can be used in your experiment.

farrhax D as mines

for (e) say u have mention 50cm3 gas syringe
1 mol ---> 12dm3 or (0.012cm3)
x mol ---> 50cm3

get the mols and multiply it by its mr u'll gets its mass

 

[tom ed]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_51.pdf
just wanted to discuss the plan in the 1st question....and the diagram of the apparatus..

 

[dman7000]

farrhax D as mines

for (e) say u have mention 50cm3 gas syringe
1 mol ---> 12dm3 or (0.012cm3)
x mol ---> 50cm3

get the mols and multiply it by its mr u'll gets its mass

thanks wasa abit confused from the markscheme

 

[dman7000]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_51.pdf
just wanted to discuss the plan in the 1st question....and the diagram of the apparatus..

i think the apparatus to use is something similar to the one used in question 3 in paper 52 oct nov 2009