Methane (CH4) diffuses 1.458 times as fast as a certain closely related gaseous compound. Which of the following could be the unknown gas? CO2, C2H6, CH3Br, CH3I, or CH3F
To determine the unknown gas, we need to find the gaseous compound that diffuses 1.458 times slower than methane (CH4).
The rate of diffusion of a gas is inversely proportional to the square root of its molar mass.
Let's calculate the molar masses for each option:
- CO2: carbon dioxide has a molar mass of 44 g/mol.
- C2H6: ethane has a molar mass of 30 g/mol.
- CH3Br: methyl bromide has a molar mass of 94.9 g/mol.
- CH3I: methyl iodide has a molar mass of 141 g/mol.
- CH3F: methyl fluoride has a molar mass of 34 g/mol.
Now, we compare the molar masses:
- The molar mass of CH4 is 16 g/mol.
- The molar mass of CO2 is 44 g/mol, which is greater than that of CH4, so it will diffuse slower.
- The molar mass of C2H6 is 30 g/mol, which is lower than that of CH4, so it will diffuse faster.
- The molar mass of CH3Br is 94.9 g/mol, which is greater than that of CH4, so it will diffuse slower.
- The molar mass of CH3I is 141 g/mol, which is greater than that of CH4, so it will diffuse slower.
- The molar mass of CH3F is 34 g/mol, which is lower than that of CH4, so it will diffuse faster.
Based on the comparison, the only gaseous compound that could diffuse 1.458 times slower than methane (CH4) is CO2 (carbon dioxide).