Calculating Molarity of Nitric Acid Solution

How do we calculate the molarity of a nitric acid solution?

Given that a bottle of nitric acid has a density of 1.423 g/mL and contains 70.9% nitric acid by weight.

What is the molarity?

Calculating the Molarity of Nitric Acid Solution

The molarity of the nitric acid solution can be determined by first calculating the number of moles of nitric acid present per liter of solution.

First, let's find the mass of nitric acid in the solution. Since the solution is 70.9% nitric acid by weight, we can assume that 100 g of the solution contains 70.9 g of nitric acid.

Next, we need to convert the mass of nitric acid to volume using its density. The density of nitric acid is given as 1.423 g/mL. By dividing the mass of nitric acid (70.9 g) by the density (1.423 g/mL), we find that the volume of nitric acid in the solution is approximately 49.89 mL.

Then, we convert the volume of nitric acid to liters by dividing by 1000, resulting in approximately 0.04989 L.

Finally, to calculate the molarity, we divide the number of moles of nitric acid by the volume of the solution in liters. The molarity is defined as moles per liter, so the molarity of nitric acid in the solution is approximately:

Molarity = moles of nitric acid / volume of solution in liters

To determine the number of moles of nitric acid, we use its molar mass. The molar mass of nitric acid (HNO3) is approximately 63.01 g/mol. By dividing the mass of nitric acid (70.9 g) by its molar mass, we find that the number of moles of nitric acid is approximately 1.125 mol.

Substituting the values into the molarity equation, we have:

Molarity = 1.125 mol / 0.04989 L

Molarity ≈ 22.54 M

Therefore, the molarity of the nitric acid solution is approximately 22.54 M.