Question 39

Simultaneously in solid, liquid, and gas phases

The triple point of a substance is the specific temperature and pressure at which the substance can coexist in solid, liquid, and gas phases simultaneously. This unique condition is critical in understanding phase transitions.

A) As a gel with solid and liquid trapped in gas

This option is incorrect because a gel does not represent the phases defined by the triple point. A gel generally consists of a solid matrix and liquid, but it does not include the presence of gas as a phase that can coexist with solid and liquid at specific conditions.

B) Simultaneously in sol, gel, and plasma phases

This option is incorrect as it misrepresents the phases involved in the triple point. Sols, gels, and plasmas are not the correct phases; the triple point specifically involves solid, liquid, and gas phases of a single substance.

C) Simultaneously in solid, liquid, and gas phases

This option accurately describes the triple point. At this unique condition, a substance can exist in all three phases—solid, liquid, and gas—at the same time, which is a fundamental concept in thermodynamics.

D) As a sol with gas and solid trapped in liquid

This option is incorrect because it does not accurately define the phases involved at the triple point. A sol typically refers to a liquid suspension of solid particles, which does not capture the coexistence of the fundamental phases of matter required for the triple point.

Conclusion

The correct answer is C, as it precisely identifies the coexistence of solid, liquid, and gas phases at the triple point. All other options fail to accurately represent the defined phases relevant to this thermodynamic concept, reinforcing the importance of understanding phase transitions in substances.