Acertain substance, x, has a triple-point temperature of 20°c at a pressure of 2.0 atm.

which one of the following statements cannot possibly be true?

a) x can exist as a liquid above 20°c.

b) x can exist as a solid above 20°c.

c) liquid x can exist as a stable phase at 25°c, 1 atm.

d) both liquid and solid x have the same vapor pressure at 20°c.

e) all of these statements could be true

The statement which could possibly not be true is C -" Liquid X can exist as a stable phase at 25°C, 1atm."

Explanation:

Triple point is the point where a substance co-exist as solid liquid and gas. At any point other than the triple point, the substance exist as a single phase substance.

As shown in the diagram, Liquid cannot exist as a stable phase at 1atm( below the the triple point pressure of 2atm) as the liquid can only exist beyond the pressure of triple point.

im not exactly sure but i think its b!