Macromolecules - 2021 MCQs

Which of these is not a type of self-assembly?

• Directed self-assembly, in which a template is used to assist the self-assembly process.

• Post-modification, in which self-assembly involves the organization of several units prior to a final structure.

• Strict, which is fully reversible and represents the global thermodynamic minimum.

• Incommensurate, in which the product leads to a structural evolution which is dynamic.

Stereoisomers that are nonsuperimposable mirror images of each other are known as:

• cis-trans isomers.

• diastereoisomers.

• enantiomers.

• anomers.

In which of the following molecules is hydrogen bonding likely to be the most significant component of the total intermolecular forces?

• CH₄

• CO₂

• C₆H₁₃NH₂

• CH₃OH

What types of intermolecular forces exist between HI and H₂S?

• Dipole-dipole and ion-dipole

• Dispersion forces, dipole-dipole, and ion-dipole

• Dispersion forces and dipole-dipole

• Dispersion forces only

The image below represents two polar molecules with permanent dipole moments. Which orientation represents the lowest energy state?

• 1

• 2

• 3

• Both 2 and 3

Based on the molecular mass and dipole moment of the five compounds in the table below, which should have the highest boiling point?

• CH₃CH₂CH₃

• CH₃OCH₃

• CH₃Cl

• CH₃CN

What term best describes the nature of the interaction between the two molecules in the co-crystal shown in the figure below? The interaction is shown by the dashed lines.

• Ion-dipole interaction

• Halogen bond

• Anion π interaction

• Hydrogen bond

What type of information can be obtained from a Scanning Electron Microscope (SEM) that is not easily accessible from a Transmission Electron Microscope (TEM)?

• Atomic-level resolution of internal structures

• Chemical composition of individual atoms

• Surface topography and texture of the sample

• Electron diffraction patterns of crystallized materials

A true statement about hydrophobic interactions is that they:

• are the driving force in the formation of micelles of amphipathic compounds in water.

• do not contribute to the structure of water-soluble proteins.

• have bonding energies of approximately 20–40 kJoule per mole.

• involve the ability of water to denature proteins.

Which statement is INCORRECT?

• Nanoscale materials have structural features (e.g. particle size or grain size) of at least one dimension in the range of 1–100 nm.

• The top-down approach synthesises nanomaterials from atomic molecular species via chemical reactions or self-assembly of molecular constituents.

• At the nanoscale, unique optical, magnetic, electrical, and other properties emerge.

• Allotropes of carbon include graphene, nanotubes, fullerene, diamond, and graphite.