How many grams of NaOH are needed to make 100 ml of a 0.2m solution of NaOH?

To calculate the grams of NaOH needed, use the formula:

mass (g) = molarity (M) x volume (L) x molar mass (g/mol).

First, convert 100 ml to liters by dividing by 1000. Then, plug in the values for molarity (0.2 M), volume (0.1 L), and molar mass of NaOH (40 g/mol) to find the answer: mass (g) = 0.2 x 0.1 x 40 = 0.8 grams of NaOH.