i) The atmospheric pressur on Pluto is 3 microbars. Express this pressure in bars, kPa, atm, and torr.
ii) A scientist uses an ultra-high vacuum chamber that has a pressure of 6.5 x 10^-12 torr. If the temperature is 298 K, how many molecules are there in 2.0 cm^3? What is the molar volume, in L/mol, at that temperature.