Question

Ice floats in water at 0°C. Why is this an example of physical equilibrium? a)The system is closed; nothing leaves the system. b)No new substances form when the water molecules change state. c)The forward and reverse processes occur at different rates.

Answer 1

Answer: Option (b) is the correct answer.

Explanation:

Physical equilibrium is defined as a system in which there will occur no change in the physical state of substance. For example, at zero degree celsius water is present in both liquid and solid state as follows.

      $H_{2}O(l) \rightleftharpoons H_{2}O(s)$

For a system to be present in physical equilibrium is as follows.

The system must be a closed system.

It should be dynamic in nature.

There will occur no change in measurable property along with change in time.

Thus, we can conclude that ice floats in water at $0^{o}C$ this an example of physical equilibrium because no new substances form when the water molecules change state.