We need a 3.0M aqueous HCl solution to dissolve the middle of a penny which is made of nickel. What mass of HCl is contained in 2.40 L of a 3.0M solution?

262.44 grams of HCl is contained in 2.40 L of a 3.0 M solution.

Explanation:

Molarity (M) or Molar Concentration is the number of moles of solute that are dissolved in a certain volume.

Molarity is calculated as the number of moles divided by the volume of the solution:

Molarity is expressed in units .

In this case:

Replacing:

and solving you get:

number of moles of solute= 3 M* 2.40 L

number of moles of solute= 7.2 moles

Being the molar mass of HCl 36.45 g/mole, then you can apply the following rule of three: if 1 mole has 36.45 grams, 7.2 moles how much mass does it have?

mass of HCl= 262.44 grams

262.44 grams of HCl is contained in 2.40 L of a 3.0 M solution.