Which has highest freezing point at 1 atm? a)0.1 molal NaCl solutionb)...
Sugar solution has i=1 so ΔTf minimum so Tf will be maximum.
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Which has highest freezing point at 1 atm? a)0.1 molal NaCl solutionb)...
Introduction:
The freezing point of a solution is the temperature at which it changes from a liquid to a solid state. The freezing point of a solution is lower than that of the pure solvent due to the presence of solute particles. This phenomenon is known as freezing point depression. The extent of freezing point depression depends on the concentration of the solute particles in the solution.
Explanation:
The freezing point depression of a solution can be calculated using Raoult's law. According to Raoult's law, the vapor pressure of a solvent above a solution is proportional to the mole fraction of the solvent in the solution. The decrease in vapor pressure of the solvent results in a decrease in its freezing point.
In this case, we are comparing the freezing points of different solutions: a 0.1 molal NaCl solution, a 0.1 molal BaCl2 solution, a 0.1 molal sugar solution, and a 0.1 molal FeCl3 solution.
Freezing point depression:
The freezing point depression is directly proportional to the concentration of the solute particles in the solution. Hence, the solution with the highest concentration of solute particles will have the greatest freezing point depression and the lowest freezing point.
Comparison:
To determine which solution has the highest freezing point at 1 atm, we need to consider the number of solute particles each solution provides.
- NaCl: NaCl dissociates into Na+ and Cl- ions in solution. Therefore, 0.1 molal NaCl solution provides 0.1 molal of Na+ ions and 0.1 molal of Cl- ions. This means it provides a total of 0.2 molal of solute particles.
- BaCl2: BaCl2 dissociates into Ba2+ and 2Cl- ions in solution. Thus, 0.1 molal BaCl2 solution provides 0.1 molal of Ba2+ ions and 0.2 molal of Cl- ions. This means it provides a total of 0.3 molal of solute particles.
- Sugar: Sugar does not dissociate into ions in solution. Therefore, a 0.1 molal sugar solution provides 0.1 molal of solute particles.
- FeCl3: FeCl3 dissociates into Fe3+ and 3Cl- ions in solution. Hence, 0.1 molal FeCl3 solution provides 0.1 molal of Fe3+ ions and 0.3 molal of Cl- ions. This means it provides a total of 0.4 molal of solute particles.
Conclusion:
Comparing the concentrations of solute particles in the different solutions, we find that the 0.1 molal FeCl3 solution has the highest freezing point depression and, therefore, the lowest freezing point. Thus, the correct answer is option 'D', 0.1 molal FeCl3 solution.
Which has highest freezing point at 1 atm? a)0.1 molal NaCl solutionb)...
Non eloctrolyte have highest freezing point