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Chemistry: Post your doubts here!

Pals_1010

Pals_1010

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xxfarhaxx said:
bt its da sme i all...if u c da increase in mols..it increases by 0.25..so y cnt it b A??
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Capture.PNG

If the first division was 0.5 then the second division should be 1.0 then A isnt correct. As 1.0 moles of oxygen doesnt correspond to Al
 
xxfarhaxx

xxfarhaxx

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Gémeaux

Gémeaux

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XPFMember said:
Assalamoalaikum wr wb!

Got some doubts in P1 :unsure:
Got some doubts in P1 :unsure:

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View attachment 8282View attachment 8283View attachment 8284View attachment 8285View attachment 8286View attachment 8287View attachment 8288View attachment 8289
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26. A is dehydration, C is acid hydrolysis of esters. D is mixture of ketone and an oxidizing agent, and ketones do not oxidize. B is an aldehyde with an oxidizing agent which will oxidize aldehyde, and reduce itself... a redox reaction occurs.

40. such reaction pathway diagram will only be of a reaction that consists of two steps occuring separately for the reaction to cmplt. this happens when tertiary haloalkane will react with NaOH in an SN1 mechanism.
images


20. A fits into the description given. B does not react with aq. NaOH. C is a gas at 25°C. D does not mix with water cmpltly.

35. Solubility of group II metals increases down the group so Ba is more soluble than Ca. Ca will form a white suspension and Ba will dissolve. Both being alkaline earth metals will turn litnus blue. and in each case H2 will be produced.

37. contaminants mainly are two: N2 and S. the question says X is solid so sulphur will be the option. continue on now with S. its oxide SO2 is formed in car engines? yes. it *cud* be oxidized if provided with suitable conditions.
1)SO2 has lone pairs as it bonds with 2 atoms of Oxygen. 2) without vanadium pentaoxide (catalyst) the reaction cannot occur spontaneously in atmosphere. 3) SO2 is colorless.

hope it helps =)
 
histephenson007

histephenson007

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There are two possible isotopes for Cl. But the molecule is Cl2. So, there can be three possible peaks.

1. 2 atoms of 35Cl form a Cl2
2. 2 atoms of 37Cl form a Cl2
3. 1 atom of 35Cl and 1 atom of 37Cl form the Cl2.

I dunno what the (+) charge on the Cl2 is about. But I think it has something to do with the mass of an electron being negligible.
 
melly713

melly713

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rehan751 said:
I don't know about 29's reason but I know that Alkene obtained from dehydration of but-2-nol will have 3 isomers so 3 alkenes. So B

For 30, Please view the picture in full size otherwise you'll find it too small:

http://img685.imageshack.us/img685/8421/001jwvf.jpg

Remember there is no need for writing down full structures as you obviously won't have enough time but I did to explain it. Just have a look at only the double bonded carbons for cis-trans isomerism, if they have any 1 similar element or group on both side it shows cis-trans isomerism.

Similarly only look at single-bonded carbon for optical and see if any carbon has 4 different groups or elements surrounding it.]
Click to expand...
] hey for the pic im seeing a photo of a frog in an icecube im not seeing anything else?
 
melly713

melly713

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hi
saudha said:
i dint get 29.... but got 30
30 30 Which compound exhibits both cis-trans and optical isomerism?
A CH3CH=CHCH2CH3
B CH3CHBrCH=CH2
C CH3CBr=CBrCH3
D CH3CH2CHBrCH=CHBr

a compound which contains both optical isomer ( a C compound with 4 different group, a chiral centre) and a cis-trans isomerism

a- cannot be optical, as non of the carbon is a chiral centre,whereas it has cis-trans isomerism.
b-does not have cis-trans isomerism
c-has cis-trans but not optical isomerism
d -has both cis - trans and a chiral centre
you have to draw and workout , and you will get the right answer
so d is the answer.
hope you understand, if u dont pls ask the doubt
Click to expand...
how can i look for a chiral if there is a double bond ? im only seeing 3 groups?
 
Most_UniQue

Most_UniQue

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Can someone explain me what are chiral compounds with examples? I searched the net but cudnt understand
 
XPFMember

XPFMember

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alphabravocharlie said:
25: First one: cracking, requires high temperature
2nd and 3rd: Substitution reaction, require heat
So D remains

37: Y is CO dude :D

20: no other option is right
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Aoa wr wb!
jazakAllah khairen..thnx a lot

...i actually didnt know substituition reactions require heat :eek: i probably forgot :eek:
 
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