21.

The first order rate constant for dissociation of N₂O₅ is 6.2 x 10^-4 s^-1 .The half-life period (in s) of this dissociation will be :

• 1117.7

• 111.7

• 223.4

• 160.9

The IUPAC name of the compound :

 is :

• 2 - ethyl - 2 - methyl - 3 - hexanone

• 5 - ethyl - 5 - methyl - 4 - hexanone

• 5 , 5 - dimethyl - 4 - heptanone

• 3 , 3 - dimethyl - 4 - heptanone

The gas phase reaction of nitric oxide and bromine yields nitrosyl bromide :

2NO (g) + Br₂ (g) $\to$ 2NOBr (g)

The rate law is rate = k[NO]²[Br₂]

The overall reaction order is :

• 1

• 2

• 3

• 4

Fungicides are organic compounds of :

• mercury

• fluorine

• lead

• chlorine

CO binds itself to metal atoms through :

• carbon atom only

• oxygen atom only

• carbon and oxygen atom

• does not bind

In the periodic table actinides occupy :

• III B group in 7th row

• III B group in 6th row

• III B group in 5th row

• None of the above

During electrochemical process :

• Gibbs free energy increases

• Gibbs free energy remains constant

• no prediction can' be made about Gibbs free energy

• Gibbs free energy decreases

At same temperature which pair of the following solutions are isotonic ?

• 0.2 M BaCl₂ and 0.2 M urea

• 0.1 M urea and 0.1 M NaCl

• 0.1 M NaCl and 0.1 M K₂SO₄

• 0.1 M Ba(NO₃)₂ and 0.1 M Na₂SO₄

Which of the following is diamagnetic ?

• CuCl₂

• NiCl₂

• FeCl₃

• Cu₂Cl₂

Why Sc (Z = 21) is not considered as transition element ?

• Properties of Sc are similar to alkali metals

• 3d - orbitals are empty in its stable compound

• Stable oxidation number of Sc is +2

• Atomic volume of Sc is very large