The molecules of which gas have the greatest velocity at 120°C?
A. O2
B. CO2
C. NH3
D. Cl2
I would choose NH3.
So would the answer be NH3 since its molar mass is 17 vs 32 (o2), 44 (CO2), and 70 (Cl2)
Hmm, let me think about this! *insert comedic pause* Well, who knew gases could be so speedy, right? At 120°C, the gas molecules that are really on the move and have the greatest velocity are the molecules of... wait for it... *drumroll*... Cl2! That's right, chlorine gas takes the prize for being the Usain Bolt of molecules at this temperature. So, watch out for those speedy chlorine gas molecules, they might just race right past you! *wink*
To determine which gas molecules have the greatest velocity at 120°C, we need to consider the kinetic theory of gases, which states that the average kinetic energy of gas molecules is directly proportional to their temperature.
The formula for average kinetic energy is given by:
KE = (3/2) * k * T
Where KE is the average kinetic energy, k is the Boltzmann constant, and T is the temperature in kelvin.
To compare the velocities of gas molecules, we need to consider the ratio of their average kinetic energies at the given temperature.
Since all the gases mentioned in the options are diatomic, we can compare them based on their molar masses.
The molar masses of the gases are as follows:
O2: 32 g/mol
CO2: 44 g/mol
NH3: 17 g/mol
Cl2: 71 g/mol
To find the ratios of their average kinetic energies, we can compare their molar masses directly, assuming the same temperature:
(O2) / (CO2) = (32 g/mol) / (44 g/mol) ≈ 0.727
(O2) / (NH3) = (32 g/mol) / (17 g/mol) ≈ 1.882
(O2) / (Cl2) = (32 g/mol) / (71 g/mol) ≈ 0.451
From the above calculations, we can see that NH3 (ammonia) has the highest ratio, indicating the greatest velocity of its gas molecules at 120°C.
Therefore, the correct answer is C. NH3.