Chemistry: Post your doubts here!

[sksuriza]

states at standard room temperature and pressure!!!
RING A BELL

 

[Silent Hunter]

http://www.xtremepapers.com/CIE/Interna ... 7_qp_2.pdf

Q2 (c)

How to do after this:

(0.1 + x )^2 = 4
(0.5 - x)^2

 

[abcde]

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9701%20-%20Chemistry/9701_s07_qp_2.pdf

Q2 (c)

How to do after this:

(0.1 + x )^2 = 4
(0.5 - x)^2

Square root both sides in an attempt to solve the equation for x.
=> (0.1 + x)/(0.5 - x) = 2
=> x = 0.3
Insert x into your expressions for equilibrium moles: (0.1 + 0.3) = 0.4 and (0.5 - 0.3) = 0.2.

 

[Silent Hunter]

Thank You.

and what about http://www.xtremepapers.com/CIE/Interna ... 9_qp_2.pdf

Q3 d (ii) ?

 

[abcde]

It is very much the same. What about it?

 

[unique840]

Thank You.

and what about http://www.xtremepapers.com/CIE/Interna ... 9_qp_2.pdf

Q3 d (ii) ?

[(0.2 + x)^2] / [(0.5 - x)^2] = 1.44
(0.2 + x) / (0.5 - x) = 1.2
0.2 + x = 0.6 - 1.2x
2.2x = 0.4
x = 0.18

CO2 AND H2 = 0.5 - 0.18
CO AND H2O = 0.2 + 0.18

 

[Silent Hunter]

http://www.xtremepapers.com/CIE/Interna ... 4_qp_1.pdf

q10 ??

and one more thing:

its about electrolysis, that when we have to right overall equations .... we have to write all the half equations and then cancel those on both sides...? correct?

Thank You

 

[Silent Hunter]

http://www.xtremepapers.com/CIE/Interna ... 4_qp_1.pdf

Q1

help please.Paper tomorrow

 

[talhajohar]

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9701%20-%20Chemistry/9701_s04_qp_1.pdf

Q1

help please.Paper tomorrow

 

[Silent Hunter]

Why have you multiplied by 2 , 3 1 etc? in each option?

 

[Nibz]

^ To get the moles of one atom present in that molecule.
In CO2 -> One Carbon atom and 2 Oxygen atoms. So x 3
In Methane -> One Carbon atom and 4 Hydrogen atoms. So x 5
Likewise, in Neon there is only one. So x1 and in Ozone there are 3 Oxygen atoms. So x3

 

[Silent Hunter]

Thanks alot

 

[Silent Hunter]

http://www.xtremepapers.com/CIE/Interna ... _qp_12.pdf

How to do Q.7 ?

Thank You

 

[Nibz]

Final Pressure = pHe + pNe
=> (Volume of He/Total Volume) x Pressure of He + (Volume of Neon/Total Volume) x Pressure of Neon
=> (5/15) x 12 + (10/15) x 6
=> 4 + 4 = 8 kPa
Answer A

 

[Silent Hunter]

what formula are we using?

 

[Nibz]

P1V1 + P2V2 = P3V3

 

[Silent Hunter]

http://www.xtremepapers.com/CIE/Interna ... _qp_12.pdf

Q11

 

[OakMoon!]

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9701%20-%20Chemistry/9701_w10_qp_12.pdf

Q11

All the questions you have posted require the same concept. So you should first concentrate on correcting your concept instead of solving more questions. Here is a simple way to get hold of it. Use the terms initial amount, amount reacted, amount formed and equilibrium amount to tackle such questions. The question is solved in the following way:

 

[jason234]

i need helpp with these questions

 

[talhajohar]

i need helpp with these questions