Question

Kinetic energy of gas depends on:
A.Temperature
B.Pressure
C.Surface area
D.Both A and B

Answer 1

Hint: We have to know that temperature and pressure are macroscopic properties of gases. These properties are associated with molecular motion that is a microscopic phenomenon. The kinetic theory of gases correlates between macroscopic properties and microscopic phenomena. The study of motion is kinetics, and in this case motion of gas molecules.

Complete step by step answer:
We have to know that in an ideal gas, there are no attractive forces between the molecules of gas. Inside the molecules, there is no rotation or vibration motion. The kinetic energy of the translational motion of an ideal gas is dependent on its temperature.
The kinetic energy is measured in terms of Joules (J), and the temperature is measured in terms of Kelvin (K).
We can give the formula of average kinetic energy per molecule of gas as,
$K.E = \dfrac{3}{2}{k_b}T$
Here, K.E represents the average kinetic energy per molecule of the gas.
Boltzmann’s constant is represented as ${k_b}$ and its value is $1.38 \times {10^{ - 23}}\,J/K$.
T is temperature (in Kelvin)
We can also give the formula of average kinetic energy per molecule of gas as,
$K.E = \dfrac{3}{2}RT$
Here, K.E represents the average kinetic energy per molecule of the gas.
R is the gas constant.
T is temperature (in Kelvin)
We can see that kinetic energy of the gas is directly proportional to temperature. Also based on the kinetic theory of gases, the average kinetic energy of molecules of gas depends on the absolute temperature.
$K.E\alpha T$

$\therefore $ option (A) is correct.

Note:
We can give the postulates of kinetic theory of gases as,
1.Gases consist of particles such molecules or atoms, which are in constant random motion.
2.The particles of gases are constantly colliding with each other and with the walls of their container. These collisions are elastic in nature; there is no net loss of energy from the collisions.
3.The particles of gases are small and the total volume occupied by gas molecules is negligible comparative to the total volume of their container.
4.There are no interactive forces (i.e., attraction or repulsion) between the gas particles.
5.The average kinetic energy of gas particles is directly proportional to the absolute temperature of the gas, and all gases at the same temperature contain the same average kinetic energy.