Question
R_1/R_2 = squareroot MM_2/squareroot MM_1 R_1, R_2 = rates of effusion or diffusion for two gases of different massess. MM_1, MM_2 = molar masses of the two different gases. On the Molecular Labs Screen, choose Topic 25: The ability of Gases to Mix. Remove the diagram so that the gas molecules are easier to see. In the box, there are two gases separated by a barrier. The two gases are carbon monoxide, CO and hydrogen, H_2. Traditionally, carbon atoms are represented with black and oxygen is represented with red. Hydrogen atoms are represented with white. Are the number of CO molecules greater than, same as, or less than the number of H_2 molecules? Obtain a stopwatch so that the time required for either gas to fill the container can be measured. Start the simulation. Remove the barrier by right clicking on the barrier. Right click a second time to remove the barrier. When the barrier is removed, measure the amount of time requred for the H_2 gas to be evenly dispersed throughout the container. Measure the amount of time required for the CO gas to be evenly dispersed throughout the container. Time for H_2 gas: Time for the CO gas: Did the two gates disperse throughout the container at the same rate or at different rates? Repeat the process using CO_2 gas and N_2 gas. Traditionally, nitrogen is represented with blue atoms. Time for CO_2 gas: Time for the N_2 gas:
Explanation / Answer
Rate of diffusion is inversily proportional to square root of its density which implies that it is inversily proportional to square root of molar mass of gas.
So, as the mass of the gas increases its rate of diffusion will be decreased.That means time required to occupy the given volume increases with increase in molar mass.
Since, molar mass of CO is greater than H2, these two gases do not occupy through the containser at the same time. They have different rates of diffusion.
One definition of rate of diffusion relates time and molar mass as,
t1 / t2 = (M1 / M2 )1/2
t1 / t2 = (28 / 2 )1/2
t1 / t2 = 3.74
t1 = 3.74 t2
Therefore time required to ocuupy the same volume of the container for CO is 3.74 times more than that of H2.
