Question

What is the average velocity of atoms in 1.00 mol of neon (a monatomic gas) at 288k?

Answer 1

You could solve this in two ways: using the ideal gas law (Van der Waals parameters optional), or by using the density. Since you specify a pressure and temperature (in kelvin), I will use the ideal gas law. Ideal gas law: PV=nRT P = pressure = 1.00 ATM V = volume = 1.00 L n = moles = what you're solving for R = gas constant = 0.0821 L*ATM/(mol*T) (T is absolute temperature (kelvin)) T = absolute temperature = 298 K (1.00atm)(1.00L) = n(0.0821L*ATM*mol -1 T -1 )(298K) n = 0.04 moles A n = Avogadro's Number = number of molecules in one mole = 6.022141 * 10 23 0.04 * 6.022141*10 23 = 2.409 * 10 22 molecules of N 2 in 1.00L at 1.00atm and 298K