MChem Master of Chemistry Master of Chemistry: Inorganic Chemistry 3

Question 1

Which of the following is an example of a hypervalent compound that violates the octet rule?

Accepted Answer

PCl₅

Answer

PCl₅ has 10 electrons around phosphorus (5 bonding pairs), making it a hypervalent molecule that invokes d-orbital or 3-center bonding descriptions.

Question 2

The 18-electron rule predicts that which of the following complexes is coordinatively unsaturated?

Accepted Answer

[V(CO)₆]

Answer

V has 5 valence electrons; six CO ligands donate 12 electrons, giving 17 total electrons—one short of the 18-electron count, making [V(CO)₆] coordinatively unsaturated.

Question 3

In solid-state chemistry, the rock salt structure adopted by NaCl can be described as:

Accepted Answer

Na⁺ in octahedral holes of an FCC Cl⁻ lattice

Answer

In NaCl, Cl⁻ ions form an FCC lattice and Na⁺ ions occupy all octahedral holes, giving each ion a coordination number of 6.

Question 4

Which property distinguishes a Type II (high-Tc) superconductor from a Type I superconductor?

Accepted Answer

Type II exhibits two critical fields (Hc1 and Hc2) with a mixed Abrikosov vortex state between them

Answer

Type II superconductors have two critical fields: below Hc1 full Meissner effect operates, between Hc1 and Hc2 magnetic flux penetrates as vortices, and above Hc2 superconductivity is lost.

Question 5

In VSEPR theory, which molecular geometry results from an AX₄E₂ electron domain arrangement?

Accepted Answer

Square planar

Answer

AX₄E₂ has 6 electron domains (4 bonding + 2 lone pairs) arranged octahedrally; the two lone pairs occupy axial positions, giving a square planar molecular geometry.

MChem Master of Chemistry Practice Test

MChem Master of Chemistry Practice Test

MChem Master of Chemistry Master of Chemistry: Inorganic Chemistry 3