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ALL CIE CHEMISTRY DOUBTS HERE !!

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Deadly_king:

--- Quote from: $!$RatJumper$!$ on November 18, 2010, 05:44:03 pm ---Many thankx.. may god bless you DK :)
I jus dont understand, why did you divide -2/2? as in where did the -2 come from?

--- End quote ---

No problem buddy :)

So first you should realise that this is a redox reaction such that one substance must get oxidised and another one reduced.

We have found that the change in oxidation number of S is +2, i.e it has been oxidised. So there should be another substance which has undergone same oxidation state but in the other direction, i.e which has been reduced. In this case it's the metal M.

So the change in oxidation number of the metal should be -2. Since there are two atoms of it, we divide by 2. ;)

Hope it helps :)

Deadly_king:

--- Quote from: Dania on November 18, 2010, 06:52:20 pm ---The answer is A.

--- End quote ---

Both reactions, i.e with bromine and hydrogen under respective conditions will occur at the C=C. Both of them will break the 2 C=C bonds, each with one molecule.

One molecule of H2 is required to break one C=C bond to form the corresponding alkane. Since there are two C=C, two moles of H2 will be required.

The same applies for bromine. ;)

Hope it helps :)

komailnaqvi:
N04 Q10!!!!!!!!!!!!!!!!!!!!!!!! plzzzzzzzzzzzzzzzzzzzzzzzzzz

Deadly_king:
Nov 04 No 10

2H2O(g) <==> 2H2(g) + O2(g)

Initially there is only pressure of 1 atm due to steam.

                                  (H2O)                        (H2)                        (O2)
Initially                             1                              0                               0

At equilibrium                 1 - 2                          2                            

Since we have been told that 20% of the steam has been converted, this implies that there still remains 80% at equilibrium.

So 1 - 2 = (80/100) x 1 -----> = 0.1

So the total pressure at equilibrium will be [(1 - 2) + 2 + ] ----> Replace = 0.1 to get a total of 1.1 atm.

Now we can find each partial pressure at equilibrium by dividing by total pressure.

(H2O) = (1 - 2)/1.1 ----> 0.8/1.1
I'll let you find the other by yourself. ;)

Answer is D.

Jun 10 p11 No 40

Bromoethane has a lower boiling point(39oC) than the solution from which it is being made, so as it is formed, the heat supplied will cause it to evaporate and we'll be able to collect it using the apparatus shown.

Ethanal also has a lower boiling point(21oC) that the reactants producing it. So it can be successfully separated using the apparatus.

1, dibromoethane however has a much higher boiling points(132oC) than the other substances in the reacting mixture. Hence we'll not be getting it through this apparatus.

So answer is B.

Hope it helps :)

komailnaqvi:
thanx man.
J05 Q2 plz
+rep

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