Which of the following ions is paramagnetic?

• Cu⁺⁺

• Zn⁺⁺

• Ni⁺⁺

• Both 'a' and 'c'

The molecule having largest dipole moment among the following is

• CHI₃

• CH₄

• CHCl₃

• CCl₄

753.

Pick out the incorrect statement from the following :

• sp hybrid orbitals are equivalent and are at an angle of 180° with each other

• sp² hybrid orbitals are equivalent and bond angle between any two of them is 120°

• sp³d² hybrid orbitals are equivalent and are oriented towards corners of a regular octahedron

• dsp² hybrid orbitals are equivalent with a bond angle of 90° between the two atoms

Which of the following electronic configurations has maximum energy?

The hybridisation of the central atom in BrF₅ molecule is :

• sp³

• dsp²

• sp³d²

• d³sp³

A covalent molecule AB₃ has pyramidal structure. The number of lone pair and bond pair of electrons in the molecule a respectively :

• 2 and 2

• 0 and 2

• 3 and 1

• 1 and 3

The AsF₅ molecule is trigonal bipyramidal. The hybrid orbitals used by the As atoms for bonding are

• d_x²-y², d_z², s, p_x, p_y

• d_xy, s, p_x, p_y, p_z

• d_x²-y², s, p_x, p_y

• s, p_x, p_y, p_z, d_z²

Hydride of boron occurs as B₂H₆ but B₂Cl₆ does not exist. This is because

• p$\mathrm{\pi }$ - d$\mathrm{\pi }$ back bonding is possible in B₂H₆ but not in B₂Cl₆

• boron and hydrogen have almost equal values of electronegativity

• boron and chlorine have almost equal atomic sizes

• small hydrogen atoms can easily fit in between boron atoms but large chlorine atoms do not.

Assertion : trans-Pent-2-ene is polar but trans- but-2-ene is non-polar.

Reason : The polarity of cis-isomer is more than trans-isomer, which are either non-polar or less polar.

• 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 : The number of tetrahedral voids is double the number of octahedral voids.

Reason : The size of the tetrahedral voids is half of that of the octahedral void.

• 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.