Assertion : SeCl₄ does not have a tetrahedral structure.

Reason : Se in SeCl₄ has two lone pairs.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Green chemistry means such reactions which

• are related to the depletion of ozone layer

• study the reactions in plants

• produce colour during reactions

• reduce the use and production of hazardous chemicals.

Identify the final product.

• 

• 

• 

• None of these

${\mathrm{C}}_6{\mathrm{H}}_{6 }\underset{{\mathrm{H}}_2{\mathrm{SO}}_4}{\overset{{\mathrm{HNO}}_3}{\to }} \mathrm{X} \underset{{\mathrm{FeCl}}_3}{\overset{{\mathrm{Cl}}_2}{\to }} \mathrm{Y}$

In the above sequence Y can be

• 3-nitrochlorobenzene

• 1-nitrochlorobenzene

• 4-nitrochlorobenzene

• none of these

Which of the following is aromatic?

Assertion :Tertiarycarbonium ions are generally formed  more easily than primary carbonium ions.

Reason : Hyperconjugation as well as inductive effect due to additional alkyl groups stabilize tertiary carbonium ions.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Pyrrole is an aromatic heterocyclic compound.

Reason : It has cyclic delocalised 6$\mathrm{\pi }$ electrons.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

For the reaction, 2NO₂ + F₂ $\to$2NO₂F,  following mechanism has been provided.

${\mathrm{NO}}_{2 }+ {\mathrm{F}}_2 \stackrel{\mathrm{slow}}{\to } {\mathrm{NO}}_2\mathrm{F} + \mathrm{F}$

${\mathrm{NO}}_{2 } + \mathrm{F} \stackrel{ \mathrm{fast}}{\to }{\mathrm{NO}}_2\mathrm{F}$

Thus, rate expression of the above reaction can be written as

• r= k [NO₂]₂[F₂]

• r = k [NO₂][F₂]

• r = k [NO₂]

• r = k [F₂]

19.

What is the correct relationship between the pHs of isomolar solutions of sodium oxide (pH₁), sodium sulphide (pH₂), sodium selenide (pH3) and sodium telluride (pH₄)?

• pH₁ > pH₂ = pH₃ =pH₄

• pH₁ <pH₂ < pH₃ <pH₄

• pH₁ < pH₂ > pH₃< pH₄

• pH₁> pH₂ > pH₃ > pH₄
  
  

Which of the following is considered as an anticancer species?