The property which is not true about fluorine is

• most of its reactions are exothermic

• it forms only one oxo acid

• highest electronegativity

• high F-Fbond dissociation enthalpy

Which is true regarding nitrogen?

• Less electronegative

• Has low ionisation enthalpy

• d-orbitals are available

• Ability to form $\mathrm{p\pi }-\mathrm{p\pi }$ bonds with itself

The number of isomers possible for the octahedral complex [CoCl₂(en)(NH₃)₂]⁺ is

• two

• three

• no isomer

• four isomers

The bivalent metal ion having maximum paramagnetic behaviour among the first transition series elements is

• Mn²⁺

• Cu²⁺

• Sc²⁺

• Cu⁺

When a brown compound of Mn (A) is treated with HCl, it gives a gas (B). The gas (B) taken in excess reacts with NH₃ to give; an explosive compound (C). The compounds A, B and C respectively are

• A - MnO₂; B - Cl₂; C - NCl₃

• A - MnO; B - Cl₂; C - NH₄Cl

• A - Mn₃O₄; B - Cl₂; C - NCl₃

• A - MnO₃; B - Cl₂; C - NCl₂

Mn²⁺ compounds are more stable than Fe²⁺ compounds towards oxidation to their +3 state, because

• Mn²⁺ is more stable with high 3^rd ionisation energy

• Mn²⁺ is bigger in size

• Mn²⁺ has completely filled d-orbital

• Mn²⁺ does not exist

As per IUPAC norms, the name of the complex [Co(en)₂(ONO)Cl]Cl is

• chlorido bis (ethane-1, 2-diamine) nitro-O-cobalt (III) chloride

• chlorido bis (ethylenediamine) nitro-O-cobalt (III) chloride

• chlorido di (ethylenediamine) nitrocobalt (III) chloride

• chloro ethylenediaminenitr-O-cobalt (III) chloride

48.

Reactivity order of halides for dehydrohalogenation is

• R - F > R - Cl > R - Br > R - I

• R - I > R - Br > R - Cl > R - F

• R - I > R - Cl > R - Br > R - F

• R - F > R - I > R - Br > R - Cl

Replacement of Cl of chlorobenzene to give phenol requires drastic conditions, but Cl of 2, 4-dinitrochlorobenzene is readily replaced. This is because

• -NO₂ group makes the ring electron rich at ortho and para-positions

• -NO₂ group withdraws electrons from meta-position

• -NO₂ donates electrons at meta-position

• -NO₂ withdraws electrons from ortho and para-positions

In the reaction,

Ethanol $\stackrel{{\mathrm{PCl}}_5}{\to } \mathrm{X} \stackrel{\mathrm{alc}. \mathrm{KOH}}{\to } \mathrm{Y} \underset{{\mathrm{H}}_2\mathrm{O}, ∆}{\overset{{\mathrm{H}}_2{\mathrm{SO}}_4, \mathrm{room} \mathrm{temp}}{\to }} \mathrm{Z}$

The product Z is

• C₂H₄

• CH₃CH₂OCH₂CH₃

• CH₃CH₂OSO₃H

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