The label on a bottle of concentrated HCl says the contents are 36% HCl by mass and have a density of 1.179 g/mL. What is the Molarity of the Conc. HCl. . The conc HCl was diluted 50 % with water, to 721 mL.which was then reacted with 35.4 g of Al. How many grams of hydrogen can be theoretically formed?. How much of which reactant will be left after the reaction is over?