Main group elements and their compounds

Main group elements and their compounds: Allotropy, synthesis, structure and bonding, industrial importance of the compounds.

YEAR JUN-2016 DEC-2015 JUN-2015 DEC-2014 JUN-2014 DEC-2013 JUN-2013 DEC-2012 JUN-2012 DEC-2011 JUN-2011
No.of questions appeared 5   4 6 3 2 7 5 2 3 4 5

1.Among the halides, NCl3(A), PCl3(B) and AsCl3(C), those which produce two different acids.

(a) A and B

(b) A and C

(c) B and C

(d) A, B and C

 

2.The correct structure of P4 S3 is:

p4s3

 

3.The reaction that yields Li AlH4 is:

(a) HCl( excess)+ AlCl3+ Li—>

(b) H2+ Al+ Li—>

(c) LiH (excess)+ AlCl3—>

(d) LiH(excess) +Al—>

 

4.Boric acid is a weak acid in aqueous solution. But its acidity increases significantly in the presence of ethyleneglycol, because

(a) ethylene glycol releases additional H+

(b) B(OH)4- is consumed in forming a compound with ethylene glycol.

(c) ethylene glycol neutralizes H+ released by boric acid.

(d) Boric acid dissociates better in the mixed-solvent.

 

5.For the deposition of Pb by electroplating, the best suited compound among the following is

 (a) PbCl2

(b) PbSO4

(c) Pb(Et)4

(d) Pb(BF4)2

 

6.The correct order of the retention of cations on a sulfonated cation exchange resin column is

(a) Ag+> K+> Na+> Li+

(b) K+> Na+> Ag+> Li+

(c) Li+> Na+> K+> Ag+

(d) Li+> Na+> Ag+>  K+

 

 

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