VITEEE 2016 :: Chemistry :: General questions

• Chemistry - General questions

The correct set of quantum numbers for Rb (atomic number .37 ) is

Answer:

Explanation:

The electronic configuration for Rb (37) is 

 Rb (37)

  = 1s²  2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰  4p⁶ 5s¹

 For  5s¹, n=5, l=0, m=0 s= $-\frac {1}{2}$

Name of the catalyst used to bring  down the reaction

Answer:

Explanation:

 The most widely used method for preparing aromatic amines is the reduction of the nitro group to the amino group. This reduction can be achieved by catalytic hydrogenation, or most frequently with an acid and a metal (Fe, Zn, Sn)  or a metal salt like SnCl₂.

$C_{6}H_{5}NO_{2}$           $\underrightarrow{ H_{2}, Catalyst}$              $C_{6}H_{5}NH_{2}$

 Nitrobebenzene              or (i) Sn, HCl,(ii) OH^-                           Aniline

Which of the following complex will show fac &  mer isomerism?

Answer:

Explanation:

 Complexes of the type ${M_{A_{3}}}_{B_{3}}$  exist in two geometrical  forms which are named as facial (fac-) and meridonal (mer-isomers)

$[Co(NH_{3})_{3}(NO_{2})_{3}]$ may be represented in fac- and mer- isomeric forms as follows.

Coordination number of Co in  $[Co(NH_{3})_{6}]Cl_{3}$

Answer:

Explanation:

The number of atom of the ligands  that are directly bound to the central metal atom or ion by coordinate bond is known as the coordination number of the metal atom or ion. Hence the coordination no .of the given compound will be 6

 The product P for the above given reaction will be

Answer:

Explanation:

Nitric acid not only nitrates but also oxidizes the highly reactive ring as well, with loss of much material as dark-coloured tar. Furthermore, in the strongly acidic nitration medium, the amine  is converted into anilinium  ion (-NH₃⁺): substitution is thus controlled not by the -NH₂ group but the -NH₃ ⁺ group  which because of its positive charge  directs the entering  group to the meta-position instead of ortho,  and para

However, all these difficulties are overcome by protecting the amino group by acetylation, with either acetyl chloride or acetic anhydride. Acetylation (-NH₂→ NHCOCH₃) coverts -NH₂ group to acetamido (-NHCOCH₃) group which is 0, p-directing but lesser activating toward electrophilic aromatic substitution than the parent -NH₂ group.

• Chemistry - General questions