Question

The average molecular speed in a sample of Ar gas at a certain temperature is 391 m/s. The average molecular speed in a sample of Ne gas is ______ m/s at the same temperature.

Answer 1

550 m/s

Step-by-step explanation:

The average molecular speed (v) is the speed associated with a group of molecules on average. We can calculate it using the following expression.

`v = \sqrt{(3 * R * T)/(M) }`

where,

• R: ideal gas constant

• T: absolute temperature

• M: molar mass of the gas

We can use the info of argon to calculate the temperature for both samples.

`T = (v^(2) * M)/(3 * R) = ((391m/s)^(2) * 39.95g/mol)/(3 * 8.314J/k.mol) = 2.45 * 10^(5) K`

Now, we can use the same expression to find the average molecular speed in a sample of Ne gas.

`v = \sqrt{(3 * R * T)/(M) } = \sqrt{(3 * (8.314J/k.mol) * 2.45 * 10^(5)K )/(20.18g/mol) } = 550 m/s`