Question

In the given phase diagram for a pure substance, regions I, II, III, IV, respectively represent 

• A. Vapor, Gas, Solid, Liquid
• B. Gas, Vapor, Liquid, Solid
• C. Gas, Liquid, Vapor, Solid
• D. Vapor, Gas, Liquid, Solid

Hint:

In a phase diagram, the regions correspond to the states of matter, and the boundaries between them represent phase transitions such as melting, boiling, and sublimation.

Answer 1

The Correct Option is B

Step 1: Understanding the phase diagram.
In the phase diagram of a pure substance, each region corresponds to a different phase of the substance. The regions in the diagram are labeled according to the physical states: vapor, gas, liquid, and solid. The phase boundaries represent the transitions between these phases. The critical point marks the end of the liquid-gas phase boundary.

Step 2: Analyzing the options.
(A) Vapor, Gas, Solid, Liquid: Incorrect. This does not follow the usual ordering of phases in a phase diagram.
(B) Gas, Vapor, Liquid, Solid: Incorrect. The correct order is different.
(C) Gas, Liquid, Vapor, Solid: Incorrect. This does not reflect the correct phase arrangement.
(D) Vapor, Gas, Liquid, Solid: Correct. This ordering represents the correct sequence of regions in the phase diagram.

Step 3: Conclusion.
The correct answer is (D) Vapor, Gas, Liquid, Solid, as this represents the proper phase transitions in a typical phase diagram.