Question

Which of the following statement is correct? (1) The vapour pressure of ortho hydrogen is more than that of para hydrogen. (2) The specific heat of ortho hydrogen is more than that of para hydrogen. (3) The conductivity of ortho hydrogen is smaller than that of para hydrogen. (4) All are correct.

Short answer

All are correct.

Step-by-step solution

Understand ortho and para hydrogen

Ortho and para hydrogen are two different spin isomers of molecular hydrogen. Ortho hydrogen has parallel nuclear spins, while para hydrogen has antiparallel nuclear spins. These differences impact various properties such as vapor pressure, specific heat, and conductivity.

Analyze vapor pressure

Vapour pressure is related to the energy states of the molecules. Ortho hydrogen, with parallel spins, has slightly higher energy and results in a slightly higher vapor pressure compared to para hydrogen.

Analyze specific heat

The specific heat of a substance is determined by the energy required to raise the temperature of a given quantity. Ortho hydrogen, having higher rotational energy levels, also has a higher specific heat compared to para hydrogen.

Analyze conductivity

Conductivity in this context likely pertains to thermal conductivity. Ortho hydrogen tends to have lower thermal conductivity compared to para hydrogen due to differences in their molecular interactions and energy distribution.

Consolidate the choices

From the analysis, the statements that are correct are: (1) The vapor pressure of ortho hydrogen is more than that of para hydrogen, (2) The specific heat of ortho hydrogen is more than that of para hydrogen, and (3) The conductivity of ortho hydrogen is smaller than that of para hydrogen. Therefore, statement (4) All are correct is accurate.

Key concepts

Spin Isomers

Ortho and para hydrogen are examples of spin isomers of molecular hydrogen. This means that they have different spin configurations for their protons. In the ortho form, the protons' spins are parallel, while in the para form, they are antiparallel. This difference in spin configuration affects various physical properties such as vapor pressure, specific heat, and thermal conductivity. Understanding these differences is essential to grasp how each form behaves in different conditions and applications.

Vapor Pressure

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase. It is an important property that indicates how a substance will behave when it transitions between different states of matter. Ortho hydrogen has parallel nuclear spins, which gives it slightly higher energy compared to para hydrogen. This results in a higher vapor pressure for ortho hydrogen. In contrast, para hydrogen, with its antiparallel spins, has lower energy and therefore a lower vapor pressure.
This difference can be crucial in applications where precise control over hydrogen's phase behavior is necessary.

Specific Heat

Specific heat is the amount of energy required to raise the temperature of a specific quantity of a substance by one degree Celsius. Ortho and para hydrogen differ in their specific heats due to their unique rotational energy levels. Ortho hydrogen, which has higher rotational energy levels due to parallel spins, also has a higher specific heat. This means that more energy is needed to increase its temperature compared to para hydrogen.
Understanding specific heat is vital not only in chemistry but also in real-world applications where temperature regulation and energy efficiency are critical.

Thermal Conductivity

Thermal conductivity is the property of a material to conduct heat. In the context of hydrogen, thermal conductivity is influenced by molecular interactions and energy distribution among the molecules. Ortho hydrogen exhibits lower thermal conductivity compared to para hydrogen. This is due to the nature of its parallel spin configuration, which results in less efficient heat transfer compared to the antiparallel configuration of para hydrogen.
This attribute is significant in various industrial processes and technologies where efficient heat transfer is essential for performance and safety.