You need to make a 300 ml of a .37M Na2 SO4 solution. How much Na2 So4 should you weigh out?

Answer 1

How many moles do you need? That's mols = M x L = 0.37M x 0.300 L = ?
Then mols = grams/molar mass. YOu know mols and molar mass, solve for grams.

Answer 2

Also, check assay label for purity. If less than 100% pure, divide grams by fractional purity.