Assertion : B₂ molecule is diamagnetic.

Reason : The highest occupied molecular orbital is of σ type.

• 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.

The paramagnetic species is

• KO₂

• SiO₂

• TiO₂

• BaO₂

The ion which is not tetrahedral in shape is

• BF₄^-

• NH₄⁺

• Cu(NH₃)₄²⁺

• NiCl₄^2-

The statement true for ${\mathrm{N}}_3^{-}$ is

• it has a non-linear structure

• it is called pseudohalogen

• the formal oxidation state of nitrogen in this anion is -1

• it is isoelectronic with NO₂

Which of the following molecule has highest bond energy ?

• F-F

• N-N

• C-C

• O-O

Shape of O₂F₂ is similar to that of

• C₂F₂

• H₂O₂

• H₂F₂

• C₂H₂

The ONO angle is maximum in

• ${\mathrm{NO}}_3^{-}$

• ${\mathrm{NO}}_2^{-}$

• ${\mathrm{NO}}_2$

• ${\mathrm{NO}}_2^{+}$

208.

The number of $\mathrm{\sigma }$ and $\mathrm{\pi }$ bonds present in pent-4-ene, I-yne is :

• 10 , 3

• 4 , 9

• 3 , 10

• 9 , 4

The dipole moment is the highest for

• trans-2-butene

• 1,3-dimethylbenzene

• acetophenone

• ethanol.

Which of the following are arranged in the decreasing order of dipole moment?

• CH₃Cl, CH₃Br, CH₃F

• CH₃Br, CH₃Cl, CH₃F

• CH₃Cl, CH₃Br, CH₃F

• CH₃Br, CH₃F, CH₃Cl