Arrange the following gases in order of increasing average molecular speed at 25 °C. A) Cl₂

Question

Arrange the following gases in order of increasing average molecular speed at 25 °C. A) Cl₂< O₂< F₂< N₂ B) Cl₂< F₂< O₂< N₂ C) Cl₂< F₂< N₂< O₂ D) F₂< O₂< N₂< Cl₂ E) N₂< F₂< Cl₂< O₂

Quizplus · Accepted Answer

The average molecular speed of a gas is directly proportional to the square root of its temperature and inversely proportional to the square root of its molar mass. At a constant temperature of 25 °C, the gases with lighter molar masses will have higher average molecular speeds than those with heavier molar masses.

So, among the given options, the gas with the lightest molar mass is hydrogen (not given in the options) but among the given options, fluorine (F) has the lightest molar mass of 19 g/mol, followed by oxygen (O) with a molar mass of 32 g/mol, nitrogen (N) with a molar mass of 28 g/mol, and chlorine (Cl) with a molar mass of 71 g/mol.

Therefore, the gases arranged in order of increasing average molecular speed at 25 °C are: Cl2 < O2 < N2 < F2, which matches option B.

Arrange the Following Gases in Order of Increasing Average Molecular