A 20.00 liter container holds 5.00 g of helium ( He, AW = 4.0g/mol ), 5.00 g of nitrogen ( N, AW = 14.0g/mol ) and 5.00 g of argon ( Ar, AW = 39.9 g/mol ) at 25 C. What is the partial pressure of each gas and total pressure of the mixture of gaases, in atmospheres, in the container?