Question

in the phase diagram shown here:
the line oc is almost vertical because the melting point of a solid
is not very sensitive to changes.
a true
b false

Explanation:

Step1: Understand phase diagram

In a phase diagram, the line OC represents the solid - liquid equilibrium (melting point line).

Step2: Analyze melting point sensitivity

The melting point of a solid is not very sensitive to pressure changes. A vertical line in a pressure - temperature phase diagram implies that a large change in pressure causes only a small change in the melting temperature.

Answer:

a. TRUE