# A bottle with a capacity of 0.1 m ^ 3 contains 4 * 10 ^ 25 oxygen molecules.

**A bottle with a capacity of 0.1 m ^ 3 contains 4 * 10 ^ 25 oxygen molecules. The gas pressure in the cylinder is 2 * 10 ^ 5 Pa. What is the average kinetic energy of oxygen molecules?**

To calculate the required value of the average kinetic energy of oxygen molecules, we apply the formula: P = 2/3 * n * Ekin = 1.5 * (N / V) * Ekin, from where we can express: Ekin = 1.5 * V * P / N

Data: V – capacity of the oxygen cylinder (V = 0.1 m3); P is the pressure in the cylinder (P = 2 * 10 ^ 5 Pa); N is the number of oxygen molecules (N = 4 * 10 ^ 25 molecules).

Let’s make a calculation: Ekin = 1.5 * V * P / 2N = 1.5 * 0.1 * 2 * 10 ^ 5 / (4 * 10 ^ 25) = 7.5 * 10 ^ -22 J.

Answer: The molecules of taken oxygen, according to the calculation, have an average kinetic energy of 7.5 * 10 ^ -22 J.