A gaseous mixture at a constant temperature contains O2, CO2 and He. List the three gases in order of increasing average molecular speed. THANKS.
Vrms = sqrt(3RT/M)
Molar mass is in the denominator; therefore, the V decreases as the molar mass increases.
To determine the order of increasing average molecular speed of the gaseous mixture, we need to consider the factors that affect the molecular speed.
1. Molecular Mass: Generally, lighter molecules have higher speeds compared to heavier molecules at the same temperature.
2. Temperature: Higher temperatures result in increased molecular speed.
In this case, we have a gaseous mixture of O2, CO2, and He. Let's compare the molecular masses of these gases:
- Oxygen (O2) has a molecular mass of approximately 32 g/mol.
- Carbon dioxide (CO2) has a molecular mass of approximately 44 g/mol.
- Helium (He) has a molecular mass of approximately 4 g/mol.
Since lighter molecules tend to have higher speeds, we can rank the gases accordingly:
1. Helium (He) - It has the lowest molecular mass among the three gases.
2. Oxygen (O2) - It has an intermediate molecular mass.
3. Carbon dioxide (CO2) - It has the highest molecular mass among the three gases.
Therefore, the correct order of increasing average molecular speed for the gaseous mixture is He < O2 < CO2.