How many grams of sodium sulfate Na's must be added to make 500 ml of M sodium sulfate solution?

To determine the grams of sodium sulfate needed, you first need to specify the molarity (M) of the sodium sulfate solution. Once you have the molarity, you can use the formula: grams = molarity (M) x volume (L) x molar mass (g/mol). This will give you the amount of sodium sulfate in grams needed to make the solution.