Chemistry: Post your doubts here!

[DragonCub]

If you read the question carefully enough, it states there's a cyclohexene ring and not a cyclohexane ring that the compound contains.
I guess there's no easier way to do this than to draw a quick small structure structure and count the number of hydrogen we're getting. :|

Alright... Then there are 13 C and 18 H left. (26-18)/2 = 4, so 4 double bonds in the aliphatic chain. Plus the one in cyclohexene there are 5.

 

[DPratik]

​

Can someone please give explanations to these paper 1 questions?​

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http://www.xtremepapers.com/papers/...d AS Level/Chemistry (9701)/9701_w08_qp_1.pdf​

Q3 What does 'ground state' mean? And r we supposed to write the '1s2 2s2....' electronic configuration to know the answer?​

Q21 Does an alcohol get oxidised by hot, concentrated manganate(7) ions?​

Q31 Why is the answer B not A? all the three statements seem correct.​

and Q38 Why cant the answer be B?​

ground state means when the electron are at the lowest level,yeah you are supposed to right it so that it may be easy for you to answer it

hey it surely would get becuase KMnO4 is an oxidizing agent which means alcohol can get oxidized

for question 31) you can see that there is the presence of most electronegative element of periodic table, N and O so which means permanent dipole can't form because both the element would try to attract the bonded electron towards itself !!


and for question 38) in fire extinguisher Br* free radical is generated to stop the combustion which means the answer must be option 1 and option 2 but i am not sure about why the answer is only option 1 but do note that in fire extinguisher Br * radical is generated !!

 

[selena]

please can anyone give me notes on isomerism and polymerization?

 

[hassam]

reply urgent for 2nd prt.....i guess there is insufficient info .......cos how will i know the mass of co2 lost

 

[tom ed]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w02_qp_1.pdf

can any body help me wd Q10 and 11......

 

[hassam]

well this is a definition of lattice energy the energy change when 1 mole of (ionic)
solid/crystals is formed from its gaseous ions.
er mentions candidates lost mark for not specifying that a solid was formed......is it necessaryy......cant l.e be used for ionic liquids

 

[DPratik]

hey can anyone provide me the notes of transition metals ? and worksheet of enthalpy changes(As) ??

 

[shan5674]

can someone explain or give me notes on chemical bonding and structure as well as enthaply cycles and calculations please

 

[JD REBORN]

http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
In Q34 why is statement 1 true?

 

[gary221]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
In Q34 why is statement 1 true?

i think its true bcoz since sulfuric acid is a stronger acid, it'll react faster, nn so reach a higher temp faster...

 

[JD REBORN]

i think its true bcoz since sulfuric acid is a stronger acid, it'll react faster, nn so reach a higher temp faster...

Sorry need a better explanation...

 

[JD REBORN]

http://www.xtremepapers.com/papers/...d AS Level/Chemistry (9701)/9701_s09_qp_1.pdf
Q11 Why cant answer be D
Q13 What to do in this?
Q31 How can radius be same?
Q34,Q35,Q37

 

[Jaf]

can any body help me wd Q10 and 11......

I can not believe it... question 11 took me half a page to do. -_____-

 

[gary221]

I can not believe it... question 11 took me half a page to do. -_____-

?

 

[Jaf]

?

There's way too much Algebra involved in the question. Any one not good at Mathematics will almost certainly screw this up.

 

[gary221]

ur damn right...
that is a teaser...
i think ill probably end up blind guessing ths ques...the time wont suffice

 

[gary221]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s09_qp_1.pdf
Q11 Why cant answer be D
Q13 What to do in this?
Q31 How can radius be same?
Q34,Q35,Q37

hmm..nt sure abt 11 n 13
31 is easy though.. since Carbon n Cl r in d same period, they hv d same no. of shells, n so the radius of both r the sme, whreas d othr properties dnt match up, so D

 

[JD REBORN]

hmm..nt sure abt 11 n 13
31 is easy though.. since Carbon n Cl r in d same period, they hv d same no. of shells, n so the radius of both r the sme, whreas d othr properties dnt match up, so D

They are not in the same period

 

[gary221]

in 34 v hv 2 remembr d defn of Bronsted Lowry theory, tht acids r proton donors, n bases r acceptors...
so the only pt which mentions a proton donor/acceptor is d 1st, which says tht ammonia is a proton donor, which ties in wth the theory...
hence D is d ans

 

[gary221]

They are not in the same period

sorry...m bad..
wht do u thnk it'll be thn??
coz m blank...