The question asks for another name for intermolecular forces. We need to evaluate each option to determine which one correctly identifies or describes intermolecular forces.
B) Van der Waals forces — a collective term for all intermolecular attractive forces except hydrogen bonding. This option correctly identifies Van der Waals forces as a category of intermolecular forces, encompassing various types of attractions between molecules. While hydrogen bonding is also an intermolecular force, Van der Waals is often used to refer to the other, generally weaker, types.
The question asks for the correct definition of Dispersion Forces, also known as London forces. We need to evaluate each option based on the characteristics of different types of intermolecular forces.
Correct Option: A) Temporary (instantaneous) attractive forces between temporarily polarised molecules caused by the momentary unequal distribution of electrons — present in ALL atoms and molecules including non-polar ones
This question asks about dipole-dipole forces, which are a type of intermolecular force. To answer correctly, one needs to understand the conditions under which these forces arise.
Correct Option: C) Polar molecules (permanent dipoles) — molecules with a net dipole moment attract each other through electrostatic interactions between their positive and negative ends
This option correctly defines dipole-dipole forces. These forces are a result of the electrostatic attraction between the oppositely charged ends of two polar molecules. Polar molecules have a permanent dipole moment due to an uneven distribution of electron density.
The question asks about Dipole-Induced Dipole forces. We need to identify the correct scenario where these specific intermolecular forces occur. This involves understanding the nature of different types of intermolecular forces.
A) A molecule with a permanent dipole moment and an adjacent non-polar (or weakly polar) molecule — the permanent dipole induces a temporary dipole in the non-polar molecule
This option accurately describes the conditions for dipole-induced dipole forces. A polar molecule's permanent dipole creates an electric field that can distort the electron cloud of a nearby non-polar molecule, creating a temporary, induced dipole in the non-polar molecule. The attraction between the permanent dipole and the induced dipole constitutes the dipole-induced dipole force (also known as Debye forces).
The question asks for the correct definition of a hydrogen bond. We need to recall the specific conditions and atoms involved in forming a hydrogen bond.
Correct Option: C) A hydrogen atom covalently bonded to a highly electronegative atom (F, O, or N) and a lone pair of electrons on another electronegative atom (F, O, or N) in the same or different molecule
This option correctly defines a hydrogen bond. The hydrogen atom, being bonded to a highly electronegative atom (F, O, or N), acquires a significant partial positive charge. This partially positive hydrogen is then attracted to the lone pair of electrons on another highly electronegative atom (F, O, or N), forming the hydrogen bond. This interaction can occur within the same molecule (intramolecular) or between different molecules (intermolecular).
The question asks to arrange different types of intermolecular forces in increasing order of their strength. We need to recall the relative strengths of these forces and then order them accordingly.
B) London forces < Dipole-induced dipole forces < Dipole-dipole forces < Hydrogen bonding. This order correctly represents the increasing strength of the intermolecular forces.