Chapter U6, Problem 8STP

Interpretation Introduction

Interpretation:

The reason for the reversibly holding octane smell receptors needs to be explained.

Concept introduction:

Smell molecules are the chemicals which stimulates sensory nerve cell with the non covalent interaction or weak interaction between the receptor and the molecule.

Answer to Problem 8STP

(A) intermolecular forces

Explanation of Solution

Reason for correct option:

• Smell of a molecule can be detected only by the binding of molecules with the receptors of nerve cell.
• This Binding is mainly weak non-covalent interaction such as electrostatic and Vander Waals interactions as well ashydrogen bonding.
• The force between the molecules of octane and receptor are weak intermolecular force that is the Vander Waals force.
• Octane is a homologous series of straight-chained aliphatic alkanes consisting of purely hydrocarbon structure.

Conclusion

Reasons for incorrect options:

(B) Covalent bonds.

There is covalent bonding between the C-H and C-C atoms in the octane molecules but they are together bind with weak intermolecular interactions or Vander Waals interactions.

(C) Dipole-dipole interactions.

As octane is a saturated hydrocarbon, so in octane molecule dipole interaction is not present. Dipole-dipole interaction is present only if there is an electronegative atom present such as Nitrogen, Oxygen and Flourine is present in the molecule.

(A) Hydrogen bonds:

Hydrogen bond is a weak bond which is formed when an H atom which is bonded to an electronegative atom in a molecule interacts with other electronegative atom in the other molecule. Since, octane does not have any electronegative atom thus; it will not show hydrogen bonding.