I’m having a really hard time understanding these questions. Could you please show the work and explain how you got the answers?

A large scuba tank with a volume of 18 L is rated for a pressure of 220 bar. The tank is filled at

20 °C and contains enough air to supply 1860 L of air to a diver at a pressure of 2.37 atm (a depth of 45 feet). Was

the tank filled to capacity at 20 °C?

Heavy water, D2O (molar mass = 20.03 g mol-1), can be separated from ordinary water, H2O (molar mass =

18.01), as a result of the difference in the relative rates of diffusion of the molecules in the gas phase. Calculate the

relative rates of diffusion of H2O and D2O.