Question

Assertion:
The value of van der Waals constant is larger form ammonia than for nitrogen.
Reason:
Hydrogen bonding is present in ammonia.
A. Both the assertion and reason are correct and reason is the correct explanation for assertion.
B. Both the assertion and reason are correct and reason is not the correct explanation for assertion.
C. Assertion is correct but reason is incorrect.
D. Assertion is incorrect and reason is correct.

Answer 1

Hint: We know that intermolecular forces are electrostatic in nature and embrace van der Waals forces and hydrogen bonds. Molecules in liquids are detained jointly by intermolecular interactions, which are weaker than the intramolecular interactions that grasp the atoms jointly within molecules and polyatomic ions. The intermolecular forces elevated the melting and boiling point. The three major types of intermolecular interactions are
Dipole-dipole interactions
London dispersion forces
Hydrogen bonds

Complete step by step answer:
Van der Waals constant 'a' is a not direct method to calculate intermolecular attractive force.
There are 2 styles of the element bond. They are,
Intermolecular hydrogen bond.
Intramolecular hydrogen bond.
Intermolecular element bonding: If the hydrogen bond takes place between completely different molecules of constant or different compounds, it's called building block hydrogen bonding.
Example: hydrogen bonding in water.
Intramolecular element bonding: If the hydrogen bonding takes place at intervals a molecule itself is named unit hydrogen bonding. It takes place in compounds containing two teams such that one cluster contains an atom connected to a negative atom and therefore the other cluster contains an extremely electronegative atom connected to a lesser electronegative atom of the opposite group.
We have to remember that the ammonia contains tough intermolecular forces of attraction. Intermolecular hydrogen bonding is absent in nitrogen. Hence, the value of Van der Waals constant 'a' is bigger for ammonia than for nitrogen.
So, the correct answer is Option A.

Note: Let us discuss the hydrogen bond in detail. In a molecule, when an atom is connected to an extremely electronegative atom, it attracts the shared pair of electrons more so it becomes a slightly negative end while the opposite end becomes slightly positive. The negative last part of the molecule attracts the positive last part of the opposite and as a consequence, a weak bond is made between them. This bond is called a chemical bond.