A student needs 0.2 moles of hydrochloric acid to conduct a reaction. How many milliliters of a 0.5 M HCl solution does the student need?

The student needs 0.2 moles of the reactant and is supplied with the 0.5 molar solution. To work out the number of milliliters needed, the student needs to divide the number of moles by the molarity and multiply the result by a 1000.0.2/0.5*1000=400ml