Final answer:
In a mixture of equal masses of neon and argon, neon exerts a greater partial pressure because its molar mass is lower, yielding more moles of gas and thus more collisions with the container walls. Neon has twice as many moles for the same mass compared to argon, so it exerts twice the partial pressure. The correct option is 3)
Step-by-step explanation:
When considering a mixture of equal masses of neon and argon gases, the partial pressure exerted by each gas can be determined by using Dalton's Law of Partial Pressures, which states that each gas in a mixture exerts a pressure independently of every other gas in the mixture. The number of moles of each gas can influence their respective partial pressures.
To find the answer, we first need to determine the number of moles of each gas using their respective molar masses. Neon has a formula weight of approximately 20 g/mol, and argon has a formula weight of approximately 40 g/mol. With equal masses, we have more moles of neon since it has a lower molar mass. Since the pressure a gas exerts depends on the number of molecules colliding with the walls of the container, and neon would have more molecules (more moles) for the same mass, neon will exert a greater pressure.
According to the ideal gas law, pressure is directly proportional to the number of moles (n) when volume and temperature are held constant. So, given that neon's molar mass is half that of argon, we would have twice as many moles of neon than argon for equal masses.