Some meta-directing substituents in aromatic substitution are given. Which one is most deactivating?

• $-\mathrm{C}\equiv \mathrm{N}$

• $-{\mathrm{SO}}_3\mathrm{H}$

• $-\mathrm{COOH}$

• $-{\mathrm{NO}}_2$

The radical  because it has

• 6p-orbitals and 6 unpaired electrons

• 7p-orbitals and 6 unpaired electrons

• 7p-orbitals and 7 unpaired electrons

• 6p-orbitals and 7 unpaired electrons

Which of the following compounds will not undergo Friedal-Craft's reaction easily?

• Cumene

• Xylene

• Nitrobenzene

• Toluene

How nitrobenzene is identified using Mulliken-Barker test?

Which one of the following is s-butyl phenyl vinyl methane?

On mixing alkane with chlorine and irradiating with ultraviolet light, it forms only one monochloroalkane. The alkane is

• Propane

• Pentane 

• Iso-pentane

• Neo-pentane

What is obtained when nitrobenzene is treated sequentially with (i) NH₄Cl/Zn dust and (ii) H₂SO₄/Na₂Cr₂O₇?

• meta-chloronitrobenzene

• para-chloronitrobenzene

• Nitrosobenzene

• Benzene

358.

The addition of HBr to 2-pentene gives

• 2-bromopentane only

• 3-bromopentane only

• 2-bromopentane and 3-bromopentane

• 1-bromopentane and 3-bromopentane

ethylene can be separated from acetylene by passing the mixture through

• fuming H₂SO₄

• pyrogallol

• ammoniacal Cu₂Cl₂

• charcoal powder

In the compound $\mathrm{HC}\equiv \mathrm{C}-\mathrm{C}\left({\mathrm{CH}}_3\right)={\mathrm{CH}}_2$ the hybridisation of C-2 and C-3 carbons are respectively

• sp³ and sp³

• sp² and sp³

• sp² and sp

• sp³ and sp