In (P ) versus (V ) graph, the horizontal line is found in which ____ exists.

Step-by-step solution

From the graph, at point (A, CO ₂ ) exists as a gas, As pressure is increased, the volume of the gas decreases along the curve (A B ). At (B ) liquefaction of the gas starts. Hence, volume decreases rapidly along (B C ) because liquid has much less volume than the gas. At point (C ), liquefaction is complete. Thus, along horizontal line, gas converts into liquid.