Question

In the phase diagram shown, the point Q corresponds to the triple point of water. The regions I, II and III respectively correspond to phases:

• A. liquid, solid, vapour
• B. solid, liquid, vapour
• C. liquid, vapour, solid
• D. solid, vapour, liquid

Answer 1

The correct option is A liquid, solid, vapour

In the given $P-T$ diagram,

The region $I$ consists of the water at the normal range of temperature and pressure. In that range, it exists in the form of liquid water. So, Region $I-$ Liquid

The region $II$ consists of the water in the range of high pressure and low temperature. In this range, the water exists in the form of ice. So, Region $II-$ Solid

The region $III$ consists of the water in the high range of temperature and low pressure. AT this, the water exists in the form of vapour. So, Region $III-$ Vapour

Option $\left(A\right)$ is correct.