CHEMISTRY PAPER 1

[Ashayn]

Guys let's help each other for chemistry paper 1...... Just post questions on what u don't understand and everyone else will try answer.

 

[NouranAyman]

suree!! hows your preparation for the paper, its on thursday p12

 

[Ashayn]

Not too bad... Going quite well. So what's the best approach. Should we do the same paper and discuss afterwards or u'd rather we post random questions?

 

[hino]

Not too bad... Going quite well. So what's the best approach. Should we do the same paper and discuss afterwards or u'd rather we post random questions?

can i get some help with this question 2011 pap12 Q32

 

[Ashayn]

an ideal gas obeys the equation PV=nRT if we substitute these values, we'll realise that this is not the case. The gas is at constant temperature, had there been change of state, the molecules would have lost a significant amount of kinetic enrgy, causing temperature to decrease. 3 just doesn't make sense so 1 only is correct.

 

[hino]

an ideal gas obeys the equation PV=nRT if we substitute these values, we'll realise that this is not the case. The gas is at constant temperature, had there been change of state, the molecules would have lost a significant amount of kinetic enrgy, causing temperature to decrease. 3 just doesn't make sense so 1 only is correct.

thankyou
therez a few more too i need help with 2010 oct pap12 Q 13
2007 may Q9
2007 oct Q 32,33

 

[basch]

can anyone help me with june 04 number 1

 

[hino]

can anyone help me with june 04 number 1

one mole of every element or compound contains 6.03*10^23 no. of atoms and so 1 mol of neon that is 20 g(20 is the mr of neon) contains exactly the same no. of atoms as 1mol of hydrogen that is 1g (1 is the mr of hydrogen)
the rest couldnt be right since none of them is equal to 1 mol
hope u understood it

 

[basch]

isn't the mr of H2 2 and hence the number of moles 0.5?:S

 

[hino]

ur going to take H =1 as mr and not as H2=2 bcz thats the molecular form,as an element we take the mr of hydrogen as 1

 

[candidate1]

Guys let's help each other for chemistry paper 1...... Just post questions on what u don't understand and everyone else will try answer.

sorry guys am rilly having some difficulties in chem p1,havin the paper on thursday, need help anyone

 

[candidate1]

whats the best way to pass chem p1,plsss!!!

 

[Ashayn]

whats the best way to pass chem p1,plsss!!!

Just try do as many papers as u can and make sure u understand one before you move on to the next one... All the best!!

 

[Varuna0911]

hello could u help me with Q 7 and 9 june 2012 p11

 

[NouranAyman]

guys can anyone explain about isomers! how do we name them like propan-1-ol ??? annd propan-2-ol and 2,2,dimethylpropane ??? pleaseeee

 

[NouranAyman]

http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_s10_qp_11.pdf
Q 4 , 6 , 8 and 9 pleaseee

 

[messi10]

guys can anyone explain about isomers! how do we name them like propan-1-ol ??? annd propan-2-ol and 2,2,dimethylpropane ??? pleaseeee

That is a basic concept of organic.

C-C-C-OH -- That is prop-1-ol, means OH is attached to 1st carbon - This is also primary alcohol

C-C(OH)-C -- That is prop-2-ol. OH is attached in chain to 2nd carbon. - This is also called secondary alcohol.

C-C(CH3)2-C-OH - This is 2,2 dimethylepropane, because at 2nd Carbon there are two methyl groups are attached in chain.

You must Google a bit on the Organic Naming Rules, i think you must have a good grip on those. These are organic basics.

 

[InnocentAngel]

Please help me with this question friends : I just cant figure out ...

 

[InnocentAngel]

Please can someone help me : Still having some problem with these chemical enrgetics questions :

 

[iKhaled]

Please can someone help me : Still having some problem with these chemical enrgetics questions : View attachment 18626

ok this question took me some time to get it but now i got it ! so lemme explain it for u..

ok so you see this is the hess's cycle that i drew from there we can see that the,
ΔH of formation of CO2 = -283
ΔH of formation of H2O = -268
and we also need the enthalpy change when we change the H2O(l) to H20(g) so its +44

now from the diagram i drew we can calculate ΔH which is:

ΔH = ( -286 + 44 ) - ( -283)
ΔH = 41Kj/mol which is C !!

i hope this helped u..