Chemistry: Post your doubts here!

[_Ahmad]

Sorry it is
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_11.pdf

Q13, i don't how to get this, i have got volume as 60 cm3, how is it 30 cm3
M/J 2011

i think you used V=n*24 for finding volume instead of V=n/C

 

[SIstudy]

the relation is made for just group 2 in our case
just remember, in group 2, both IE and Mpt decrease down the group

yu mean group 2 is an exception?

 

[Kamihus]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w09_qp_11.pdf
Q18 hydrocarbons are present in catalytic converters??????
and someone pls explain Q19 too

18: Just learn this and their reactions.
19: N2H4-CO is formed. NH4 and other ion is required so has to be CNO-

 

[$$AK$$]

Guys plz help me
even if only few Qs

 

[..sacrifice4Revenge..]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w09_qp_11.pdf
Q18 hydrocarbons are present in catalytic converters??????
and someone pls explain Q19 too

for 19,
u know that cyanate is CNO..
so
in the compount shown
you see two Nitrogens, our product should also have 2 N in ammonium cyanate.
so it has to be A, cz if its B, it will make 3Nitrogens.

 

[SIstudy]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s11_qp_12.pdf
Q1 (B)
like how?? in the question itself its mentioned tht it is an isotope meaning tht the number of neutrons is different :/

 

[..sacrifice4Revenge..]

yu mean group 2 is an exception?

no
for AS, group 2's trend of dec IE and Mpt has to be known only.
like that they decrease down the group.

 

[..sacrifice4Revenge..]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_12.pdf
Q1 (B)
like how?? in the question itself its mentioned tht it is an isotope meaning tht the number of neutrons is different :/

look closely,
its He and H.
not isotopes of H

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w02_qp_1.pdf
question 11 answer is D

sorry can't figure it out

 

[ZaqZainab]

ZaqZainab
so Ionisation energy affects b.pt?

means if I.E is high, the b.pt will be high?

No there is no actual relationship between B.pt and ionization energy

 

[_Ahmad]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s10_qp_11.pdf

Q21(B),31(B),40(D)

 

[SIstudy]

look closely,
its He and H.
not isotopes of H

Oh Maiii Goddd how could I do this :/ silly me
thank yu
Jazak'Allah

 

[SIstudy]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
Q9 (D)
I could make out tht glucose and fructose are structural isomers so option A and C is ruled out but cant understand how osmotic pressure is affected?

 

[NinjaXM]

How can you solve question 21 of this http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w06_qp_1.pdf
Without having to draw all of them and waste time.
Please help, I can't figure a way out.

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s07_qp_1.pdf

Q9, Explain plz


http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_11.pdf
Q13

Also, how does it hydrochloric acid behave as acid when it is added to NaCl,
And H2SO4 conc. is used for hydrolosis or dehydration, and what about NaOH,

I need urgent help !

I am really sorry to tag you but i have an urgent stituation here, i have hardly 5 minutes before i have go offline
Suchal Riaz ZaqZainab

i answered Q9 already wait i will search for it and quote it
Q13 NaCl (s) + H2SO4 (l)-------> HCl (g) + NaHSO4 (s)
it does not get reduced so it is not acting as a oxidizing agent

 

[SIstudy]

btw ppl
endothermic reactions are favoured by high temp
and exothermic reactions are favoured by low temp
in equilibrium?

 

[Kamihus]

Hey
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_11.pdf
Q1-C
Q3-D
Q6-D
Q11-A
Q12-B
Q17-D
Q21-D
Q24-C
A26-C
Q38-B
plz I NEED HELP

1-Ans is B. Cl has +5 change in ClO3. Write other options down.
3-Four atoms attached in BH4 so tetrahedral. 3 in BF3 so trigonal planar.
6-Use equation pV=nRT, convert C to Kelvin.
12-In B both has 2 lone pair and 2 bond pairs.
21- Does not possess so same on both sides.
38- I think you are confused about statement 3, PCl5 or SOCl5 is the reagent.

Just revise bond pairs.

 

[Suchal Riaz]

thts the answer

If you thought that i would go away without helping sorry to disappoint you

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s07_qp_1.pdf

Q9, Q29, Explain plz


http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_11.pdf
Q13

Also, how does it hydrochloric acid behave as acid when it is added to NaCl,
And H2SO4 conc. is used for hydrolosis or dehydration, and what about NaOH,

I need urgent help please !!!

here question 9

.

 

[princessnoor]

sorry can't figure it out

Ok