Not all units of measurement are equal, but the value of each unit is used for its intended purpose, so we have different units of measurement for each problem.
Explanation:
Flow-duration data are daily mean flow values measured over a specified time interval that have been exceeded various percentages of the specified time interval.
The answer would be .5 mols because you take the total amount of grams, which is 20, and you had up the molar mass of sodium hydroxide, which would be 40. After you have this you would set this up as a stochiometry equation. With 1 mol on top you dived 20/40 to cancel out your grams. This leaves you with .5 mols
