Question

Water at room temperature is a liquid but iron piece is a solid because

• A. Intermolecular forces between the water molecules are less.
• B. Intermolecular forces between the iron molecules are less
• C. Intermolecular spaces and kinetic energy among the water molecules are less
• D. Intermolecular spaces and kinetic energy among the iron molecules are less

Answer 1

Answer: (A), (D)

The correct options are
A

Intermolecular forces between the water molecules are less.

D

Intermolecular spaces and kinetic energy among the iron molecules are less

Water remains a liquid at room temperature because of the following reasons:

1. Intermolecular forces between the water molecules are weak.
2. Intermolecular spaces and kinetic energy among the water molecules are more.

This enables the water molecules to interchange their spaces and hence water remains in a liquid state even at room temperature.

An iron piece remains a solid at room temperature because of the following reasons:

1. Intermolecular forces among the iron molecules are very strong.
2. Intermolecular spaces, as well as kinetic energy among the iron molecules, are very small.

Thus, the molecules are held very very tightly, with the result, that the iron has a definite shape and a definite volume, and hence a solid.