The average osmotic pressure of seawater at 25 degree Celsius is approximately 30 atm. Assuming that seawater is a solution composed of NaCl and water with a salinity of 3.5%, calculate the molar mass of NaCl. The density of seawater is 1.022g/mL. (The salinity of the oceans is most often defined as the mass of salt per 1000 grams of seawater).