Calculate the concentration, in percent by mass, of a refrigerant brine solution which is 4.03 M in NaCl with a density of 1.116 g mL-1.

To calculate the concentration of a solution in percent by mass, you need to determine the mass of the solute (NaCl) and the mass of the solution.

First, let's calculate the mass of the solution:
Given density = 1.116 g mL^(-1)
Assuming we have 1 liter (1000 mL) of the solution, we can convert the density to mass by multiplying it by the volume:
mass of solution = density × volume = 1.116 g mL^(-1) × 1000 mL = 1116 g

Next, let's calculate the mass of the solute (NaCl):
Molarity of NaCl = 4.03 M
Molar mass of NaCl = 58.44 g/mol

To find the mass of NaCl, we can use the Molarity and Molar Mass using the formula:
mass of solute = Molarity × Molar mass

mass of NaCl = 4.03 M × 58.44 g/mol = 235.1732 g

Now, to calculate the concentration in percent by mass, divide the mass of the solute by the mass of the solution and multiply by 100:
concentration (in percent by mass) = (mass of NaCl / mass of solution) × 100

concentration (in percent by mass) = (235.1732 g / 1116 g) × 100
concentration (in percent by mass) ≈ 21.05 %

Therefore, the concentration of the refrigerant brine solution, which is 4.03 M in NaCl with a density of 1.116 g mL^(-1), is approximately 21.05% by mass.