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Catalogs Discussion Forums -> Non IIT Institutes -> k group rocks in bhu -> Go to message
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this is not a question just a information about k group of banaras hindu university
k group means computer science.
the B.Sc (hons) in k is one of the best proffessional degree  in bhu. there are only 30 seats in this course and admission is on the basis of uet i.e. undergraduate enterance test. there is 100% placements in M.Sc salary starting from 3 lacks to 15 lacks per annum.and it's placement is through IT bhu placement cell. and from last 2 yrs placement in B.Sc also starts in this case as last year wipro comes and he take 8 students from B.Sc and send them to bits pilani for further training and studies.
her in geophysics group placement also starts 
Catalogs Discussion Forums -> Counselling Zone -> about bit patna -> Go to message
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bit patna provides degree of bit mesra and placement of patna is also from mesra. it is only extension centre of bit mesra not a specific like pilani.
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i get electronics and electrical in birla institute of tecnology patna. is it good college or not
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English chemistry mnemonics

 

 

 

The elements Hydrogen, Nitrogen, Fluorine, Oxygen, Iodine, Chlorine, and Bromine are always found as diatomic molecules:
  • HNFOIClBr
  • HONClFIBr (say HONKLE-fibber)
  • BrINClHOF (say Brinckle-hoff)
  • Have No Fear Of Ice Cold Beer
  • Never Have Fear Of Ice Cold Beer
  • I Have No Bright Or Clever Friends
  • I Bring Clay For Our New House
  • ClIF H Bron
  • HOFBrINCl Twins (twins because they exist in pairs)
  • There are seven such elements. The first one is the first element Hydrogen; the rest form a 7 on the periodic table: N, O, F across, then going down Cl, Br, I.
  • Obsessed Cleveland Brown Fans Have No Intelligence

 Oxidation and reduction

Acronyms for oxidation and reduction:
  • Oxidation Is Losing Electrons, Reduction Is Gaining Electrons: OIL RIG
  • Electron Loss Means Oxidation: ELMO
  • Losing Electrons Oxidation, Gaining Electrons Reduction: LEO the lion. GER! or LEO says GER
Oxidation and reduction in the electrodes of an electrochemical cell:
  • Oxidation takes place at the anode (both start with vowels) reduction takes place at the cathode (both start with consonants).
  • REDuction at CAThode: RED CAT
  • ANode for OXidation: AN OX
  • Anode for Oxidation: Adults Only
  • Reduction at Cathode: Roman Catholic
  • At the AN'ode Oxidation Is Gain; and Reduction Is Loss at the CAThoed: AN OIL RIG CAT
The elements that form hydrogen bonds when bonded to hydrogren are Fluorine Oxygen Nitrogen:
  • Hydrogen is FON! (fun)
  • I think about hydrogen bonds OFN (often)
Cations are positive, while anions are negative:
  • The letter t in cation looks like a positive plus sign +: ca+ion
  • Cations are pawsitive.
  • An ANION is A Negative ION.
  • Be POSITIVE about your CATs
Metals form cations in ionic reactions
  • Metal Cat, Metal Cat, Where is my Metal Cat?
Organic ions:
  • "A hot carbonium ion is a naked carbonium ion" -- George Olah, in lecture, 1966
The sequence of dicarboxilic acids is Oxalic, Malonic, Succinic, Glutaric, Adipic, Pimelic:
  • Oh My Stars, Green Apples
  • Oh My, Such Good Apple Pie
The list of elements from most electronegative to least electronegative begins Fluorine Oxygen Nitrogen Chlorine:
  • FONCl (phone call)
Free energy equation (Gibbs-Helmholtz equation): ?G = ?H - T?S:
  • Grades = Hardship - Torture*Suffering, remembered with the terms in alphabetical sequence
Remembering sequence of alcohols,aldehydes,alkenes and alkanes
Many Elderly People Buy Picnic Hampers
Methanol Ethanol Propanol Butanol Pentanol Hexanol
Methanal Ethanal Propanal Butanal Pentanal Hexanal
Methene Ethene Propene Butene Pentene Hexene
Methane Ethane Propane Butane Pentane Hexane

 Periodic table

Period 1 of the periodic table contains H and He; period 2 contains Li, Be, B, C, N, O, F and Ne:
  • HEre LIes BEarded Bill Caught Napping On Friday.
  • He Likes Beer But Can Not Obtain Food
  • Harry, He Likes Beer By Cups Not OverFlowing
  • Harry, He Likes Beer But Cup's Not Over Flowing
  • Little Betty Boron Chews Nuts On Friday Night
  • Henry, He Likes Betty But Can Not Offer Flower Necklace
  • London BBC NO FuN
  • Liz's Better Babies Could Not Often Feel Nervous
Period 2:
  • Negress Named Magnolia Alters Sister's Photos Surprisingly Cleverly.
  • Nelly's Naughty Mg Allows Silly People Some Clatter Around Katie's Carpark
  • NaMgAl SiPS Chlorine Ardently
  • Nancy Margaret Always Sing Pop *Song Called "Arren King's Car"
Naughty Maggie Allowed Simon Put Sugar Clothes
  • Nations Might Ally Since Power Structures Clear the A[i]r [From my own college days, 1968....]
Period 3:
  • A(r) Kopper Called Scarface Tim, Very Crafty Man, (Fe) i(ro)nCogNito Cunning Zena, Gave Gertie A(s) Severe Bruise
Periods 1, 2 and 3:
  • H HeLi BeB C NO FNe Na MgAl SiPS ClArK Ca ScTiV CrMn FeCoNiCuZn GaGeAs Se BrKr
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Hydrogen Bonds

 sun laugh
(
The elements that form hydrogen bonds when bonded to hydrogren are
Fluorine Oxygen Nitrogen:
  • Hydrogen is FON! (fun)
  • Dicarboxilic Acids (electrodes)

    REDuction at CAThode: RED CAT
     red cat
    Oxidation and reduction in the electrodes of an electrochemical cell:
    • Oxidation takes place at the anode (both start with vowels), reduction takes place at the cathode (both start with consonants).
    • REDuction at CAThode: RED CAT
    • ANode for OXidation: AN OX
    • Oxidation and Reduction (electrons)

       oxidation reduction
      Acronyms for oxidation and reduction:
      • Oxidation Is Losing Electrons, Reduction Is Gaining Electrons: OIL RIG
      • Electron Loss Means Oxidation: ELMO
      • Losing Electrons Oxidation, Gaining Electrons Reduction: LEO the lion. GER! or LEO says GER
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Sentences to remember the elements

 
Periodic Table
Group 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Period
1 H He
2 Li Be B C N O F Ne
3 Na Mg Al Si P S Cl Ar
4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
6 Cs Ba * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
7 Fr Ra ** Rf Ha Sg Ns Hs Mt Uun Uuu
/
Lanthanides * La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Actinides ** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
 

Mnemonics:

1)

First eighteen elements in the periodic table:
Here He Lies Beneath Bed Clothes, Nothing On, Feeling Nervous. Naughty Margaret Always Sighs, "Please Stop Clowning Around."

(H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar.)

2)

First twenty elements in the periodic table:
Hi Hello Little Beryll Brown Cracking Nuts On Friday . Nellie's Naughty Magpie Always Sings Pop Songs Clearly After Killing Cathy

(H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca.)
Community shelf Community shelf -> vedic mathematics -> Go to message
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thanks yaar
Catalogs Discussion Forums -> Lounge -> VERY VERY INTERSTING GAME -> Go to message
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dhoom 2
a holly bolly movie

shimla or kanyakumari
Catalogs Discussion Forums -> Differential Calculus -> recommend me book -> Go to message
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i think arihant is good u may buy it
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Use the formula ALL FROM 9 AND THE LAST FROM 10 to
perform instant subtractions.
For example 1000 - 357 = 643
We simply take each figure in 357 from 9 and the last figure from 10.
So the answer is 1000 - 357 = 643
And thats all there is to it!
This always works for subtractions from numbers consisting of a 1 followed by noughts: 100; 1000; 10,000 etc.
Similarly 10,000 - 1049 = 8951
For 1000 - 83, in which we have more zeros than figures in the numbers being subtracted, we simply suppose 83 is 083.
So 1000 - 83 becomes 1000 - 083 = 917
 
Try some yourself:
 
1)  1000 - 777       =    
2)  1000 - 283       =    
3)  1000 - 505       =    
4)  10,000 - 2345  =    
5)  10,000 - 9876  =    
6)  10,000 - 1011  =    
7) 100 - 57            =    
8) 1000 - 57          =    
9) 10,000 - 321     =    
10) 10,000 - 38     =    
Top  <To top of this page
Index Alphabetical   [Index to Pages]
Using VERTICALLY AND CROSSWISE you do not need the multiplication tables beyond 5 X 5.
Suppose you need 8 x 7
8 is 2 below 10 and 7 is 3 below 10.
Think of it like this:

The answer is 56.
The diagram below shows how you get it.

You subtract crosswise 8-3 or 7 - 2 to get 5,
the first figure of the answer.
And you multiply vertically: 2 x 3 to get 6,
the last figure of the answer.
That's all you do:
See how far the numbers are below 10, subtract one number's deficiency from the other number, and multiply the deficiencies together.
7 x 6 = 42

Here there is a carry: the 1 in the 12 goes over to make 3 into 4.
Multply These:
1)  8 x 8 =
2)  9 x 7 =
3)  8 x 9 =
4)  7 x 7 =
5)  9 x 9 =
6)  6 x 6 =
 
Here's how to use VERTICALLY AND CROSSWISE for multiplying numbers close to 100.
Suppose you want to multiply 88 by 98.
Not easy,you might think. But with VERTICALLY AND CROSSWISE you can give the answer immediately, using the same method as above
Both 88 and 98 are close to 100.
88 is 12 below 100 and 98 is 2 below 100.
You can imagine the sum set out like this:
As before the 86 comes from subtracting crosswise: 88 - 2 = 86 (or 98 - 12 = 86: you can subtract either way, you will always get the same answer).
And the 24 in the answer is just 12 x 2: you multiply vertically.
So 88 x 98 = 8624
This is so easy it is just mental arithmetic.
Try some:
1)  87 x 98 =
2)  88 x 97 =
3)  77 x 98 =
4)  93 x 96 =
5)  94 x 92 =
6)  64 x 99 =
7)  98 x 97 =
Multiplying numbers just over 100.
103 x 104 = 10712
The answer is in two parts: 107 and 12,
107 is just 103 + 4 (or 104 + 3),
and 12 is just 3 x 4.
Similarly 107 x 106 = 11342
107 + 6 = 113 and 7 x 6 = 42
Again, just for mental arithmetic
Try a few:
1)  102 x 107 =
2)  106 x 103 =
3)  104 x 104 =
4)  109 x 108 =
5)  101 x123 =
6)  103 x102 =
 
Top  <To top of this page
Index Alphabetical   [Index to Pages]
The easy way to add and subtract fractions.
Use VERTICALLY AND CROSSWISE to write the answer straight down!
Multiply crosswise and add to get the top of the answer:
2 x 5 = 10 and 1 x 3 = 3. Then 10 + 3 = 13.
The bottom of the fraction is just 3 x 5 = 15.
You multiply the bottom number together.
So:
Subtracting is just as easy: multiply crosswise as before, but the subtract:
Try a few:
 
 
 
 
 
 

 

 

 
 
A quick way to square numbers that end in 5 using the formula BY ONE MORE THAN THE ONE BEFORE.
752 = 5625
75² means 75 x 75.
The answer is in two parts: 56 and 25.
The last part is always 25.
The first part is the first number, 7, multiplied by the number "one more", which is 8:
so 7 x 8 = 56

Similarly 852 = 7225 because 8 x 9 = 72.
Try these:
1) 452 =
2) 652 =
3) 952 =
4) 352 =
5) 152 =
Method for multiplying numbers where the first figures are the same and the last figures add up to 10.
32 x 38 = 1216
Both numbers here start with 3 and the last figures (2 and 8) add up to 10.
So we just multiply 3 by 4 (the next number up) to get 12 for the first part of the answer.
And we multiply the last figures: 2 x 8 = 16 to get the last part of the answer.
Diagrammatically:

And 81 x 89 = 7209
We put 09 since we need two figures as in all the other examples.
Practise some:
1)  43 x 47 =
2)  24 x 26 =
3)  62 x 68 =
4)  17 x 13 =
5)  59 x 51 =
6)  77 x 73 =
 
An elegant way of multiplying numbers using a simple pattern
21 x 23 = 483
This is normally called long multiplication butactually the answer can be written straight downusing the VERTICALLY AND CROSSWISEformula.
We first put, or imagine, 23 below 21:
There are 3 steps:
a) Multiply vertically on the left: 2 x 2 = 4.
This gives the first figure of the answer.
b) Multiply crosswise and add: 2 x 3 + 1 x 2 = 8
This gives the middle figure.
c) Multiply vertically on the right: 1 x 3 = 3
This gives the last figure of the answer.
And thats all there is to it.
Similarly 61 x 31 = 1891
6 x 3 = 18; 6 x 1 + 1 x 3 = 9; 1 x 1 = 1
Try these, just write down the answer:
1) 14 x 21
2) 22 x 31
3) 21 x 31
4) 21 x 22
5) 32 x 21
Multiply any 2-figure numbers together by mere mental arithmetic!
If you want 21 stamps at 26 pence each you can
easily find the total price in your head.
There were no carries in the method given above.,/p>
However, there only involve one small extra step.
21 x 26 = 546
 
The method is the same as above
except that we get a 2-figure number, 14, in the
middle step, so the 1 is carried over to the left
(4 becomes 5).
So 21 stamps cost £5.46.
Practise a few:
1) 21 x 47
2) 23 x 43
3) 32 x 53
4) 42 x 32
5) 71 x 72
33 x 44 = 1452
There may be more than one carry in a sum:
Vertically on the left we get 12.
Crosswise gives us 24, so we carry 2 to the left
and mentally get 144.
Then vertically on the right we get 12 and the 1
here is carried over to the 144 to make 1452.
 
6) 32 x 56
7) 32 x 54
8) 31 x 72
9) 44 x 53
10) 54 x 64
Any two numbers, no matter how big, can be
multiplied in one line by this method.
 
Multiplying a number by 11.
To multiply any 2-figure number by 11 we just put
the total of the two figures between the 2 figures.
26 x 11 = 286
Notice that the outer figures in 286 are the 26
being multiplied.
And the middle figure is just 2 and 6 added up.
So 72 x 11 = 792
Multiply by 11:
1) 43 =
2) 81 =
3) 15 =
4) 44 =
5) 11 =
77 x 11 = 847
This involves a carry figure because 7 + 7 = 14
we get 77 x 11 = 7147 = 847.
Multiply by 11:
1) 11 x  88 =
2)  11 x 84 =
3)  11 x 48 =
4)  11 x 73 =
5)  11 x 56 =
234 x 11 = 2574
We put the 2 and the 4 at the ends.
We add the first pair 2 + 3 = 5.
and we add the last pair: 3 + 4 = 7.
Multiply by 11:
1) 151 =
2) 527 =
3) 333 =
4) 714 =
5) 909 =
 
Method for dividing by 9.
23 / 9 = 2 remainder 5
The first figure of 23 is 2, and this is the answer.
The remainder is just 2 and 3 added up!
43 / 9 = 4 remainder 7
The first figure 4 is the answer
and 4 + 3 = 7 is the remainder - could it be easier?
Divide by 9:
1)  61 / 9 =     wpe4.jpg (1664 bytes)     remainder      wpe4.jpg (1664 bytes)    
2)  33 / 9 =     wpe4.jpg (1664 bytes)     remainder      wpe4.jpg (1664 bytes)    
3)  44 / 9 =     wpe4.jpg (1664 bytes)    remainder       wpe4.jpg (1664 bytes)    
4)  53 / 9  =    wpe4.jpg (1664 bytes)     remainder      wpe4.jpg (1664 bytes)    
5)  80 / 9  =    wpe4.jpg (1664 bytes)     remainder      wpe4.jpg (1664 bytes)    
134 / 9 = 14 remainder 8
The answer consists of 1,4 and 8.
1 is just the first figure of 134.
4 is the total of the first two figures 1+ 3 = 4,
and 8 is the total of all three figures 1+ 3 + 4 = 8.
Divide by 9:
6)  232 =       wpe4.jpg (1664 bytes)     remainder      wpe4.jpg (1664 bytes)    
7)  151 =       wpe4.jpg (1664 bytes)     remainder      wpe4.jpg (1664 bytes)    
8)  303 =       wpe4.jpg (1664 bytes)    remainder       wpe4.jpg (1664 bytes)    
9)  212 =       wpe4.jpg (1664 bytes)     remainder       wpe4.jpg (1664 bytes)    
10)  2121 =   wpe4.jpg (1664 bytes)     remainder       wpe4.jpg (1664 bytes)    
 
842 / 9 = 812 remainder 14 = 92 remainder 14
Actually a remainder of 9 or more is not usually
permitted because we are trying to find how
many 9's there are in 842.
Since the remainder, 14 has one more 9 with 5
left over the final answer will be 93 remainder 5
Divide these by 9:
1)  771 / 9  =       wpe4.jpg (1664 bytes)     remainder    wpe4.jpg (1664 bytes)    
2)  942 / 9  =       wpe4.jpg (1664 bytes)     remainder    wpe4.jpg (1664 bytes)    
3)  565 / 9 =        wpe4.jpg (1664 bytes)     remainder    wpe4.jpg (1664 bytes)    
4)  555  / 9 =       wpe4.jpg (1664 bytes)     remainder    wpe4.jpg (1664 bytes)    
5)  2382 / 9  =     wpe4.jpg (1664 bytes)     remainder    wpe4.jpg (1664 bytes)    
6)  7070 / 9  =     wpe4.jpg (1664 bytes)     remainder    wpe4.jpg (1664 bytes)    
 
Answers
1) 223
2) 717
3) 495
4) 7655
5) 0124
6) 8989
7) 43
8) 943
9) 9679
10) 9962
 
1) 64
2) 63
3) 72
4) 49
5) 81
6)216= 36
 
1) 8526
2) 8536
3) 7546
4) 8928
5) 8648
6) 6336
7) 9506 (we put 06 because, like all the others,
we need two figures in each part)
 
 
1) 10914
2) 10918
3) 10816
4) 11772
5) 12423
6) 10506 (we put 06, not 6)
 
1) 29/30
2) 7/12
3) 20/21
4) 19/30
5) 1/20
6) 13/15
 
1) 2025
2) 4225
3) 9025
4) 1225
5) 225
 
1) 2021
2) 624
3) 4216
4) 221
5) 3009
6) 5621
 
1) 294
2) 682
3) 651
4) 462
5) 672
 
 
1) 987
2) 989
3) 1696
4) 1344
5) 5112
 
6) 1792
7) 1728
8) 2232
9) 2332
10) 3456
 
1) 473
2) 891
3) 165
4) 484
5) 121
 
1) 968
2) 924
3) 528
4) 803
5) 616
 
1) 1661
2) 5797
3) 3663
4) 7854
5) 9999
 
1) 6 r 7
2) 3 r 6
3) 4 r 8
4) 5 r 8
5) 8 r 8
 
1) 25 r 7
2) 16 r 7
3) 33 r 6
4) 23 r 5
5) 235 r 6 (we have 2, 2 + 1, 2 + 1 + 2, 2 + 1 + 2 + 1)
 
1) 714 r15 = 84 r15 = 85 r6
2) 913 r 15 = 103 r15 = 104 r6
3) 516 r16 = 61 r16 = 62 r7
4) 510 r15 = 60 r15 = 61 r6
5) 714 r21 = 84 r21 = 86 r3
6) 2513 r15 = 263 r15 = 264 r6
7) 7714 r14 = 784 r14 = 785 r5
Community shelf Community shelf -> plzzzzzzz seeee this ....................very important................................... -> Go to message
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it is good
Catalogs Discussion Forums -> Coaching Institutes & Course Material -> about studying materials -> Go to message
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ok i will send those papers soon
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dear friends
 i have some papers on my pc if some one want it then please submit your email ids here
 
 
 
 
 
 
 
 
rate me
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Questions dealing with alkane chemistry
Problems
1. Bromination of methane is slowed down by the addition of fairly large
amounts of HBr.
a. suggest an explanation
Br . + H-CH3 ? H-Br + . CH3
?H +104 -88 = +16kcal i.e. endothermic in this direction
. CH3 + Br2 ? BrCH3 + Br .
?H = +46 -70 = -24kcal i.e. exothermic in this direction and therefore,
as soon as .CH3 forms, it reacts with Br2. Ea is low for such an
exothermic reaction.
However, as HBr is added, a competing reaction becomes possible,
the reverse of the first reaction given above:
HBr + . CH3 ? Br . + H-CH3
as ?H is ?16 kcal for this process, Ea will be very small. This reaction
removes methyl radicals and the number available for reaction with
bromine will be lessened and the reaction slows down.
b. why does HCl not react in this way
Cl . + H-CH3 ? H-Cl + . CH3
?H +104 -103 = +1kcal i.e. just endothermic in this direction. The
activation energy is +4 kcal compared with +18 for the bromination.
The activation energy for the reverse reaction is therefore +3 kcal,
higher than that for the analogous bromination reaction The methyl
radicals are also formed more readily and so are less "rare".
 
Note: Whereas part a) could be an exam question providing bond
dissociation energies are given, b) would never be?..
2. A mixture of H2 and Cl2 does not react at room temperature. At high
temperature or under the influence of light (of wavelength absorbed by
chlorine) a violent reaction takes place and HCl is formed. The
photochemical reaction yields as many as a million molecules of HCl for
each photon absorbed. The presence of a trace of oxygen slows down the
reaction.
a. propose a possible mechanism for this reaction
The fact that "the photochemical reaction yields as many as a million
molecules of HCl for each photon absorbed" indicates a chain reaction.
Initiation involves chlorine as light absorbed by chlorine begins the
process.
Cl2 ? 2Cl . (initiation)
Cl . + H2 ? HCl + H . (propagation)
H . + Cl2 ? HCl + Cl . (propagation)
2H . ? H2 (termination)
2Cl . ? Cl2
H . + Cl . ? HCl
b. explain why a mixture of H2 and I2 does not behave in the same
manner
I . + H2 ? HI + I . is very endothermic (+104 kcal to break H-H bond
whereas only 71 kcals are liberated in forming the H-I bond. Ea must
be > 33 kcal which is impossible. The corresponding reaction with
chlorine is only just endothermic, +1 kcal, and so its activation energy
is far lower.)
3. t-Butyl peroxide is a source of free radicals:
(CH3)3CO-OC(CH3)3 ? 2(CH3)3CO. (heat or light initiated)
A mixture of isobutane and CCl4 is stable at 130C. If a small amount of tbutyl
peroxide is added, a reaction occurs that yields 2-chloro-2-
 
methylpropane and chloroform. A small amount of 2-methyl-2-propanol,
(CH3)3COH, equivalent to the peroxide used, is also formed.
a. propose a mechanism which explains the formation of these products
(CH3)3CO-OC(CH3)3 ? 2(CH3)3CO.
(CH3)3CO. + (CH3)3CH ? (CH3)3COH + (CH3)3C .
(CH3)3C . + CCl4 ? (CH3)3CCl + . CCl3
. CCl3 + (CH3)3CH ? HCCl3 + (CH3)3C.
b. what is a peroxide?
a compound containing an O ? O bond
4. Why would one not prepare a Grignard reagent from bromoethanoic acid,
BrCH2CO2H?
because it contains and acidic hydrogen which would react with the
Grignard reagent as soon as it forms
5. When a mixture of methane and chlorine is irradiated, reaction begins at
once. However, when irradiation is stopped, the reaction gradually slows
down; it does not stop immediately. Why?
because it is a chain reaction and the chains continue until termination
takes place or until all of one reactant has been used up
6. The anti conformation of 1,2-dichloroethane is 1.15 kcal/mol more stable
than the gauche conformation. The two energy barriers, measured relative
to the energy of the gauche conformation, for carbon-carbon bond rotation
are 5.15 kcal/mol and 9.3 kcal/mol.
a. sketch a graph of potential energy vs. angle of rotation about the
carbon-carbon bond. Show the energy differences on your graph and
label each minimum and maximum with the appropriate conformation
of 1,2-dichloroethane.
 
b. Which conformation is present in the greatest amount? Explain.
The anti conformation is present in the greatest amount as it has the
lowest potential energy.
Synthesis
1. Propose a synthesis of n-hexane from each of the following:
a. CH3CH2CH2CH2CH2CH2Br
either treat with tri-n-butyl stannane or with Mg followed by water
b. CH3CH=CHCH2CH2CH3
hydrogen and Pt, Pd or Ni catalyst
c. CH3CH2CH2Br
1. Li, 2. CuI 3. CH3CH2CH2Br (Corey-House reaction)
2. Propose a synthesis of CH3D from CH4.
1. Br2/h? 2. Bu3SnD (or Mg followed by D2O)
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This Post 7 points    (Olaaa!! Perrrfect answer.   in 2 votes )   [?]
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(3)
SAMPLE FILE - IIT - CHEMISTRY
1. Choose the correct option. Only ONE option is correct.
1 mol of equimolar mixture of ferric oxalate and ferrous oxalate will require x mol of KMnO4 in
acidic medium for complete oxidation. Then x is
(a) 0.8 mol (b) 0.9 mol (c) 1.6 mol (d) 1.8 mol
2. Choose the correct option. Only ONE option is correct.
Predict the compounds A and B in the following reactions
CH CH ? O CH CH O h A
3 2 - 2 3 + 2 ¾¾n® ; C6H5CH CH3
CH3 O2, 95 ? 135º B
(a) CH3CH2 ? O-O-CH2CH3 and C6H5 C ? O ? OH
CH3
CH3
respectively
(b) CH3CH2? O ? O? CH2CH3 and C6H5 CH
CH3
CH2 ? O ? OH
respectively
(c) 2 3
|
3 H ? O ? CH CH
OOH
CH C and C6H5 C ? O ? OH
CH3
CH3
respectively
(d) No reaction and ? OOH
CH3
CH3
C H C
|
|
6 5 respectively
3. Choose the correct option(s), ONE or more than ONE option may be correct.
If P0 and Ps are the vapour pressure of solvent and solution respectively and N1 and N2 are
the moles of solute and solvent then :
(a)
0
s
0
(P P )
P
-
=
1 2
1
N N
N
+
(b)
0
s
s
P P
P
-
=
2
1
N
N
(c) Ps =
0
2
1 2
P .N
N +N
(d) None of these
4. Choose the correct option(s), ONE or more than ONE option may be correct.
Mg3N2 H2O A(gas) CuO B C(g) D ¾¾¾® ¾¾¾® + + H2O
C(g) can be obtained by heating
(a) (NH4)2SO4 (b) (NH4)2Cr2O7 (c) NH4NO3 (d) NH4ClO4
(4)
5. Match the items given in Column I with the items in Column II. An item of Column I can match
with more than one item from Column II. Choose the correct option from the SIX options given
below :
Match the reactions, on the left hand side with the conditions (on the right hand side), which are
most favourable for them.
Column I Column II
A. 2SO2