1) Calculate the mass of calcium chloride needed to make 250mL of a 0.3 mol/L solution. 2) Calculate the volume of 0.3mol/L calcium chloride required to prepare 100mL of 0.03mol/L calcium chloride solution. 3) Calculate the mass of sodium chloride needed to make 200mL of a 0.2mol/L solution. 4) Calculate the volume of 0.2mol/L sodium chloride required to prepare 350mL of 0.02mol/L sodium chloride solution. 5) Calculate the mass of sodium chloride needed to make 100mL of a 0.5mol/L solution. 6) Calculate the volume of 0.5mol/L sodium chloride solution required to prepare 125mL of 0.05mol/L sodium chloride solution.