Question

According to the label on a bottle of concentrated hydrochloric acid, the contents are 36.0% HCl by mass and have a density of 1.18 g/mL. What is the molarity of concentrated HCI?

Molar Concentration:
In chemistry, the term molarity usually refers to the molar concentration of a chemical mixture or solution. Typically, it is determined by the ratio of the number of moles available and the volume of the solution. The capital M (which is equal to moles per liter) is used to represent the molar or molar concentration.

Answer 1

The molarity of concentrated HCl is 11.63 M

Step-by-step explanation:

To calculate the molarity of concentrated hydrochloric acid, we need to first find the mass of HCl in 1 liter of the solution, as molarity is defined as the number of moles of solute per liter of solution.

Assuming we have 1 liter of the solution, the mass of HCl in it would be:

mass of HCl = volume of solution x density x % concentration by mass

mass of HCl = 1 L x 1.18 g/mL x 36.0%

mass of HCl = 0.4248 kg

The molar mass of HCl is 36.46 g/mol, so the number of moles of HCl in 0.4248 kg of HCl is:

moles of HCl = mass of HCl / molar mass of HCl

moles of HCl = 0.4248 kg / 36.46 g/mol

moles of HCl = 11.63 mol

Therefore, the molarity of concentrated HCl is:

molarity = moles of HCl / volume of solution

molarity = 11.63 mol / 1 L

molarity = 11.63 M

So the molarity of concentrated HCl is 11.63 M.