Question

The number of statement/s, which are correct with respect to the compression of carbon dioxide from point (a) in the Andrews isotherm from the following is ______ 

A. Carbon dioxide remains as a gas upto point (b) 
B. Liquid carbon dioxide appears at point (c) 
C. Liquid and gaseous carbon dioxide coexist between points (b) and (c) 
D. As the volume decreases from (b) to (c), the amount of liquid decreases

Hint:

In the Andrews isotherm, liquefaction begins at point (b) and ends at point (c), with \(CO_2\) existing as both liquid and gas between these points.

Answer 1

Correct Answer: 2

To determine the number of correct statements regarding the compression of carbon dioxide on the Andrews isotherm:

1. Statement A: Carbon dioxide remains as a gas up to point (b).

This statement is correct. On the Andrews isotherm, CO₂ exists as a gas until it reaches the point of condensation, labeled (b).

2. Statement B: Liquid carbon dioxide appears at point (c).

This statement is incorrect. Liquid CO₂ first appears at point (b), not (c).

3. Statement C: Liquid and gaseous carbon dioxide coexist between points (b) and (c).

This statement is correct. Between points (b) and (c), the substance is in a two-phase region where liquid and gaseous CO₂ coexist.

4. Statement D: As the volume decreases from (b) to (c), the amount of liquid decreases.

This statement is incorrect. As the volume decreases from (b) to (c), the amount of liquid increases.

Thus, the number of correct statements is 2, which fits the expected range of 2,2.