GCAP Operator 1 Practice Exam 2026 - Free GCAP Practice Questions and Study Guide

Oil and liquid ammonia are not considered miscible because they do not mix uniformly when combined. The fact that oil is less dense than liquid ammonia contributes to this immiscibility. Oil, being a non-polar substance, does not interact favorably with the polar nature of ammonia, which leads to the formation of separate layers rather than a homogeneous mixture. The density difference indicates that when added together, ammonia will sink below the oil, further demonstrating their inability to mix.

While density plays a role, the primary factor is the chemical nature of these substances—oil's hydrophobic characteristics prevent it from mixing with the hydrophilic liquid ammonia. Thus, the understanding of polarity and density establishes that the two substances will not form a miscible solution.