The number of unpaired electrons in Fe³⁺ (Z = 26 ) is

• 4

• 5

• 6

• 3

For n = 3 energy level, the number of possible orbitals (all kinds) are

• 1

• 3

• 4

• 9

In which molecule are all atoms coplanar?

• CH₄

• BF₃

• PF₃

• NH₃

4.

Inoic bonds are usually formed by combination of elements with

• high ionisation potential and low electron affinity

• low ionisation potential and high electron affinity

• high ionisation potential and high electron affinity

• low ionisation potential and low electron affinity

The angle between two covalent bonds is maximum in

• CH₄

• H₂O

• CO₂

• SO₂

If a molecule MX₃ has zero dipole moment, the sigma bonding orbital used by M (At. no. 13) are

• pure p

• sp- hybridised

• sp²- hybridised

• sp³- hybridised

CO₂ in isostructural with

• SnCl₂

• SO₂

• HgCl₂

• All of these

In 1 mole of NaCl the proton are

• 6 moles

• 11 moles

• 17 moles

• 28 moles

The molarity of a solution made by mixing 50mL of conc. H₂SO₄ (36N) with 50mL of water, is

• 36M

• 18M

• 9M

• 6M

171g of sugar cane (C₁₂H₂₂O₁₁) is dissolved in 1 L of water. The molarity of the solution is

• 2.0 M

• 1.0 M

• 0.5 M

• 0.25 M