Question

What is the concentration of h+ ions in a solution of hydrochloric acid that was prepared by diluting 15.0 ml of concentrated (11.6 m ) hcl to a final volume of 500.0 ml?

Answer 1

HCl is a monoprotic acid, which means that each mole of HCl releases one mole of hydrogen ions upon dissociation. Therefore, we calculate the moles of HCl present using:

Moles = Molarity * Volume (in liters)

Moles = 11.6 * 0.015
Moles = 0.174 moles of HCl = moles of H+ ions

Now, we use the same formula to calculate the molarity of the new solution, since the number of moles remains constant.

0.174 = M * 0.5
M = 0.348 M

The molarity of the new solution is 0.348