Commercial perchloric acid is 70.0% by mass,HClO₄(aq),and has a density of 1.67 g/mL.Calculate the molarity of perchloric acid in the solution.

Question

Quizplus · Accepted Answer

We can start by assuming we have 100 g of the solution, and therefore 70 g of HClO4. Using the density, we can calculate the volume of the solution:

density = mass/volume
1.67 g/mL = 100 g / volume
volume = 59.88 mL = 0.05988 L

Now we can use the definition of molarity:

molarity = moles of solute / liters of solution

To find the moles of HClO4, we need to use its molar mass:

H = 1 g/mol
Cl = 35.5 g/mol
O = 16 g/mol

Total molar mass = 1 + 4*16 + 35.5 = 100.5 g/mol

moles of HClO4 = 70 / 100.5 = 0.696 moles

Finally, we can calculate the molarity:

molarity = 0.696 moles / 0.05988 L = 11.6 M

Therefore, the answer is A: 11.6 M.

Commercial Perchloric Acid Is 70