Making the simplistic assumption that the dissolved nacl(s) does not affect the volume of the solvent water, determine the constants m and b in the equation molarity = mdensity + b that relates the nacl molarity to the nacl(aq) density. take the density of water to be 1.00 g/ml and the molar mass of nacl to be 58.5 g/mol.

i am having a very difficult time answering this question. there just doesn't seem to be enough information to determine the constants.

1) Variables

2) Density of the solution: mass in grams / volume in mililiters

3) Mass of NaCl: m₁

    Number of moles = mass in grams / molar mass

    ⇒ mass in grams = number of moles × molar mass

        m₁ = n₁ × MM₁

4) Number of moles of NaCl: n₁

   Molarity = number of moles / Volume of solution in liters

   M = n₁ / Vt

   ⇒ n₁ = M × Vt

5) Substitue in the equation of m₁:

   m₁ = M × Vt × MM₁

6) Substitute in the equation of density:

    d = [M × Vt × MM₁ + m₂] / (1000Vt)

7) Simplify and solve for M

Making the simplistic assumption that the dissolved NaCl(s) does not affect the volume of the solvent water means 1000Vt = V₂  

        m₂/ V₂ is the density of water: 1.00 g/mL

8) Substituting MM₁ = 58.5 g/mol

Comparing with the equation Molarity = m×density + b, you obtain: