Final answer:
The freezing point of a solution with one part salt to 11 parts water by mass can be calculated using the formula for freezing point depression, considering the dissociation of NaCl into ions and the molality of the solution.
Step-by-step explanation:
The freezing point of a saltwater solution made of one part salt to 11 parts water can be determined by calculating the solution's molality and using the freezing point depression formula. The formula to find the freezing point depression is ΔT = i * Kf * m, where ΔT is the change in freezing point, i is the van't Hoff factor (which is 2 for NaCl, as it dissociates into two ions: Na+ and Cl-), Kf is the freezing point depression constant for water (1.86°C/m), and m is the molality of the solution.
To calculate the molality (m) of the solution, you need to know the mass of the solute (salt) and the mass of the solvent (water). Assuming the solution is ideal, we calculate the moles of NaCl using its molar mass and then divide by the mass of water in kilograms to find molality. Once the molality is known, the change in freezing point can be calculated and subtracted from pure water’s freezing point (0°C) to find the new freezing point of the solution.