I have a solution made up of 100 ml of distilled water and 2.0g of NaOH. I need to determine the total volumeof the solution in order to the calculate the mass of the reaction mixture. How do I do this? We are to assume the density of the solution is the same as pure water, 1.0g/ml. Thanks.

Question

I have a solution made up of 100 ml of distilled water and 2.0g of NaOH.  I need to determine the total volumeof the solution in order to the calculate the mass of the reaction mixture.  How do I do this?  We are to assume the density of the solution is the same as pure water, 1.0g/ml.  Thanks.

DrBob222 · Answer

Since the post says "100 mL of solution" I assume that means the total volume is 100 mL and that the volume of the water is slightly less than 100 mL. The molarity = moles/L
moles = 2/40 = 0.05
0.05/0.1 = 0.5 M.