Chemistry: Post your doubts here!

[samwickz]

Ah, okay.

 

[cHeStEr]

I think the answer is C. Check in marking scheme if this is correct. If so, I'll explain what I did.

Yup its correct

 

[KurayamiKimmi]

OMG thank u sooooooooooooooooooooo freaking much!

no problem

 

[Casablanca]

Yup its correct

Okay, here goes:

CO2(g) + H2(g) -> CO(g) + H2O(g)

CO2 is being broken, so instead of -283, we take +283
H2O is being formed, so we use -286
BUT it is being formed in gaseous state, not liquid state, so we also take +44.

283 + 44 - 286 = +41.

So the answer is C.

 

[Goku]

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9701%20-%20Chemistry/9701_s03_qp_1.pdf


^ question 7 please? :/

 

[cHeStEr]

Okay, here goes:

CO2(g) + H2(g) -> CO(g) + H2O(g)

CO2 is being broken, so instead of -283, we take +283
H2O is being formed, so we use -286
BUT it is being formed in gaseous state, not liquid state, so we also take +44.

283 + 44 - 286 = +41.

So the answer is C.

Thnx a tonne..i dont undrstnd this typ of prblmes...

 

[Casablanca]

Which equation applies to an ideal gas? (p = pressure, V = volume, M = molar mass, P = density, c = concentration, R = gas constant)

1. p = PRT/M
2. pV = MRT
3. pV = cRT/M

A. 1, 2, 3
B. 1, 2
C. 2, 3
D. 1

How?

 

[samwickz]

http://www.xtremepapers.com/CIE/International A And AS Level/9701 - Chemistry/9701_s07_qp_1.pdf
Q no 9 i kinda well not kinda more lyk totally suck @ chem so any help would b lyk really cooooooooooooooooool

 

[nazzzzzz]

http://www.xtremepapers.com/papers/...d AS Level/Chemistry (9701)/9701_s06_qp_1.pdf Question 10 please. Thanks in advance

 

[nazzzzzz]

http://www.xtremepapers.com/CIE/International A And AS Level/9701 - Chemistry/9701_s07_qp_1.pdf
Q no 9 i kinda well not kinda more lyk totally suck @ chem so any help would b lyk really cooooooooooooooooool

Having the same problem

 

[geek101]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf PLEASEEEEE! thanx a bunch!

 

[KurayamiKimmi]

http://www.xtremepapers.com/CIE/International A And AS Level/9701 - Chemistry/9701_s03_qp_1.pdf


^ question 7 please? :/

PCl5-->PCl3+Cl2
bonds broken in PCl5= P-Cl bonds broken= 33o*5=1650
bonds formed in PCl3=330*3 =990
bonds formed in Cl2=240
Bonds broken-bonds formed= 1650 -(990+240)
therefore enthalpy change=+420

 

[nazzzzzz]

Which equation applies to an ideal gas? (p = pressure, V = volume, M = molar mass, P = density, c = concentration, R = gas constant)

1. p = PRT/M
2. pV = MRT
3. pV = cRT/M

Is the answer d?

A. 1, 2, 3
B. 1, 2
C. 2, 3
D. 1

How?

 

[gary221]

Which equation applies to an ideal gas? (p = pressure, V = volume, M = molar mass, P = density, c = concentration, R = gas constant)

1. p = PRT/M
2. pV = MRT
3. pV = cRT/M

A. 1, 2, 3
B. 1, 2
C. 2, 3
D. 1

How?

the ans is D...1 only as Mr = Mass/No of moles... Rearranging the equation , v gt p = P * R* T * n / Mass.
we know density = mass/ volume..so d/m = 1/volume...
Rearranging it once agn, v gt ...pv = nRT

 

[KurayamiKimmi]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf PLEASEEEEE!

which question

 

[nazzzzzz]

http://www.xtremepapers.com/papers/...d AS Level/Chemistry (9701)/9701_s06_qp_1.pdf question 16 and 10 please

 

[nerdybookworm]

URGEEEEEENNNTTTTTTTT...OCTO NOV...2011 VARIENT 11 PAPER 1...Q 6,914,15,20,23,25,28,29...plzz....


http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w11_qp_11.pdf

 

[geek101]

which question

oops sorry Q4

 

[Osake]

do you mean theoretical yied by measured yield ?=O

Yeah sorry x_x :3

 

[nerdybookworm]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s06_qp_1.pdf question 16 and 10 please

q 10 is C
cz juss leme tell yu my internet prob 4 min ok w8