JEE 2011 :: General Questions :: Chemistry

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Among the following, the number of compounds than can react with  $PCl_{5}$ to  give $POCl_{3}, $ is $O_{2}$ , $CO_{2},SO_{2},H_{2}O, H_{2}SO_{4}, P_{4}O_{10}$

Answer:

Explanation:

 $PCl_{3}$ produces $POCl_{3}$  with the following reagents

    $PCl_{5}+SO_{2} \rightarrow  POCl_{3}+SOCl_{2}$

  $PCl_{5}+H_{2}O \rightarrow   POCl_{3}+2HCl$

$ PCl_{5}+H_{2}SO_{4} \rightarrow   SO_{2}Cl_{2}+2POCl_{3}+2HCl$

  $6 PCl_{5}+P_{4}O_{10} \rightarrow  10 POCl_{3}$

The maximum number of isomers (including stereoisomers) that are possible on monochlorination of the following compounds, is

Answer:

Explanation:

I have one chiral carbon = two isomers II has two chiral carbons and no symmetry = four isomers.
III and IV have no chiral carbon, no stereoisomers

In 1L saturated solution of $AgCl[K_{sp} AgCl=1.6 \times 10^{-10}]$ 0.1 mole of $CuCl[K_{sp}[CuCl]=1.0 \times 10^{-6}]$ is added . The resulatnt conenetration  of $Ag^{+}$ in the solution is $1.6 \times 10^{-x}$ .The value of x is 

Answer:

Explanation:

It is a case of simultaneous solubility of salts with a common ion. Here solubility product of
CuCl is much greater than that of AgCl, it can be assumed that Cl^- in solution comes mainly from CuCl

$\Rightarrow$   $|Cl^{-}|=\sqrt{K_{sp}(CuCl)}=10^{-3} M$

Now for $AgCl:K_{sp}=1.6 \times 10^{-10}= [Ag^{+}][Cl^{-}]=[Ag^{+}] \times 10^{-3}$

$ \Rightarrow [Ag^{+}]=1.6 \times 10^{-7}$

The correct functional group X and the reagent/reaction conditions Y in the following schemes are  $X-(CH_{2})_{4}-X$

Answer:

Explanation:

 (a)  When   $X= COOCH_{3}CH_{3}OOC-(CH_{2})_{4}-COOCH_{3}$

(b) 

(c)

(d)   When X=CN

 In author opinion (a) and (b) should be the answer

The equilibrium  $2Cu^{1} \rightleftharpoons Cu^{0}+Cu^{II}$  in aqueous medium at 25 °C shifts towards the left in the presence of

Answer:

Explanation:

$Cl^{-},CN^{-}$ and $SCN^{-}$  forms precipitate  with Cu(I), remove Cu(I) ion from equilibrium and  reaction shifts in direction shift in the backward direction according to Le-Chatelier's principle 

• General Questions - Physics
• General Questions - Chemistry
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