Molecular formulae and shapes of some molecules are given below. Choose the incorrect match.

• NH₃ - Trigonal pyramidal

• SF₄ - Tetrahedral

• ClF₃ - T-shaped

• PCl₅ - Triginal bipyramidal

In which one of the following the central atom is sp³ hydridised?

• NH${}_4^{+}$

• BF₃

• SF₆

• PCl₅

The calculated magnetic moment of a divalent ion of an atom with atomic number 24 in aqueus solution is

• 4.90 BM

• 5.92 BM

• 3.87 BM

• 2.84 BM

Molecular shapes of SF₄ ,CF₄ and XeF₄ and the number of lone pairs on the central atom are respectively

• the same, with 1, 2 and 1

• the same with 1, 0 and 1

• different with 0, 1 and 2

• different with 1, 0 and 2

Which one of the following is not correct in respect of hybridization of orbitals?

• The orbitals present in the valence shell are hybridized

• The orbitals undergoing hybridization have akmost equal energy

• Pure atomic orbitals are more effective in forming stable bonds than hybrid orbitals

• It is not always that only partially filled orbitals participate in hybridization in some cases even filled orbitals in valence shell take part.

116.

Allyl cyanide molecule contains

• 9 sigma bonds, 4 pi bonds and no lone pair

• 9 sigma bonds, 3 pi bonds and one lone pair

• 8 sigma bonds, 5 pi bonds and one lone pair

• 8 sigma bonds, 3 pi bonds and two lone pairs

Which one of the following statements is correct?

• Ferromagnetic substance like ZnFe₂O₄ becomes paramagnetic on heating

• NaCl is a paramagentic salt

• CuSO₄ is a diamagnetic salt

• MnO is an example of antiferronmagnetic substance

In the dichromate dianion, the nature of bonds are

• for equivalent Cr-O bonds

• six equivalent Cr-O bonds and one O-O bond

• six equivalent Cr-O bonds and one Cr-Cr bond

• six equivalent Cr-O bonds and one Cr-O-Cr bond

Amongst the following ions which one has the highest magnetic moment value? (At. no. Co = 27, Ni = 28)

• [Co(NH₃)₆]³⁺

• [CoF₆]^3-

• [NiCl₄]^2-

• [Ni(CN)₄]^2-

Which among the following solid is a non-polar solid?

• Hydrogen chloride

• Sulphur dioxide

• Water

• Carbon dioxide