Calculate the molarity of a solution made by adding 33.4 mL of concentrated nitric acid (70.4 % by mass, density 1.42 g/mL) to some water in a volumetric flask, then adding water to the mark to make exactly 2000 mL of solution. (It is important to add concentrated acid or base to water, rather than the other way, to minimize splashing and maximize safety.)

First find the molarity of the concentrated HNO3.

1.42 g/mL x 1000 mL x 0.0704 x (1 mol/63g) = ? M.
Then use the dilution formula of
mL1 x M1 = mL2 x M2
33.4 x ?M = 2000 mL x M2.
Solve for M2.

To calculate the molarity of the solution, we need to first find the moles of nitric acid in the solution.

Step 1: Find the mass of nitric acid added.
Mass of nitric acid = Volume of nitric acid x Density of nitric acid
= 33.4 mL x 1.42 g/mL
= 47.428 g

Step 2: Find the mass of nitric acid in the solution.
Mass of nitric acid in solution = Mass of nitric acid x % concentration (as a decimal)
= 47.428 g x 0.704
= 33.376192 g

Step 3: Calculate the moles of nitric acid.
Moles of nitric acid = Mass of nitric acid / molar mass of nitric acid
= 33.376192 g / 63.01 g/mol (the molar mass of nitric acid)
= 0.530341015 mol

Step 4: Calculate the molarity of the solution.
Molarity = Moles of solute / Volume of solution (in liters)
= 0.530341015 mol / (2000 mL / 1000)
= 0.2651705075 M

Therefore, the molarity of the solution is approximately 0.265 M.

To calculate the molarity of the solution, we need to know the mass of the concentrated nitric acid used and its molar mass. Here's how we can calculate it step by step:

Step 1: Calculate the mass of concentrated nitric acid used (m₁):
Given that the volume of concentrated nitric acid used is 33.4 mL and its density is 1.42 g/mL, we can calculate the mass of the acid using the formula:
mass = volume × density
mass of nitric acid = 33.4 mL × 1.42 g/mL = 47.428 g

Step 2: Calculate the molar mass of nitric acid (M):
Nitric acid (HNO₃) has the atomic masses: H = 1.01 g/mol, N = 14.01 g/mol, and O = 16.00 g/mol. The molar mass of nitric acid can be calculated as follows:
M = (1 × H) + (1 × N) + (3 × O)
M = (1 × 1.01) + (1 × 14.01) + (3 × 16.00)
M = 63.012 g/mol

Step 3: Calculate the number of moles of nitric acid (n):
The number of moles of a substance can be calculated using the formula:
moles = mass / molar mass
moles of nitric acid = 47.428 g / 63.012 g/mol
moles of nitric acid = 0.7526 mol

Step 4: Calculate the volume of the solution (V):
The volume of the solution is given as 2000 mL.

Step 5: Calculate the molarity (M):
Molarity is defined as the number of moles of solute (nitric acid) divided by the volume of the solution in liters. Therefore, we can calculate the molarity as follows:
Molarity (M) = moles / volume
M = 0.7526 mol / 2 L
M = 0.3763 mol/L

Therefore, the molarity of the solution is 0.3763 mol/L.