According to the kinetic molecular theory, what is the effect of increasing temperature on the average speed of gas particles?

• A. The average speed of the particles remains unchanged.
• B. The average speed of the particles increases.
• C. The average speed of the particles fluctuates randomly.
• D. The average speed of the particles decreases.

Answer: (B)

Verified step by step guidance

1. Recall that according to the kinetic molecular theory, the temperature of a gas is directly related to the average kinetic energy of its particles.
2. Understand that the average kinetic energy (KE) of gas particles is given by the equation \(KE = \frac{1}{2} m v^2\), where \(m\) is the mass of a particle and \(v\) is its speed.
3. Recognize that the average kinetic energy is proportional to the absolute temperature \(T\) (in Kelvin), expressed as \(KE_{avg} = \frac{3}{2} k_B T\), where \(k_B\) is the Boltzmann constant.
4. Since the average kinetic energy increases with temperature, and \(KE = \frac{1}{2} m v^2\), an increase in \(T\) means an increase in the average speed \(v\) of the gas particles.
5. Therefore, increasing the temperature causes the average speed of gas particles to increase, because particles move faster as they gain kinetic energy.