If a hazardous bottle is labeled 20.2 percent by mass Hydrochloric Acid, HCl, with a density of 1.096 g/mL, calculate the molarity of the HCl solution.

Question

Quizplus · Accepted Answer

To calculate the molarity of the HCl solution, first, determine the mass of HCl in 1000 mL of solution. Since the solution is 20.2% HCl by mass, 1000 mL of this solution (with a density of 1.096 g/mL) has a mass of 1096 g, and 20.2% of this mass is HCl: $1096 g \times 0.202 = 221.392 g$ of HCl. The molar mass of HCl is approximately 36.46 g/mol, so the number of moles of HCl in 1000 mL of solution is $221.392 g \div 36.46 g/mol = 6.07$ moles. Since molarity is moles of solute per liter of solution, the molarity of the HCl solution is 6.07 M.

If a Hazardous Bottle Is Labeled 20