Final answer:
To calculate the vapor pressure of a 1 molar solution, we need to take into account the vapor pressure of pure water and the concentration of the solute. According to Raoult's law, the vapor pressure of the solution is proportional to the mole fraction of the solvent in the solution. In this case, since the solution is 1 molar, the mole fraction of the solvent is 1, and the vapor pressure of the solution will be the same as the vapor pressure of pure water, which is 12.3 kPa. Therefore, the correct option is A
Step-by-step explanation:
To calculate the vapor pressure of a 1 molar solution, we need to take into account the vapor pressure of pure water and the concentration of the solute. The vapor pressure of water at 300 K is given as 12.3 kPa. According to Raoult's law, the vapor pressure of the solution is proportional to the mole fraction of the solvent in the solution.
In this case, the solute is water and the solvent is the liquid in which it is dissolved, which is also water. Since the mole fraction of the solvent is 1 (all the particles in the solution are water molecules), the vapor pressure of the solution will be the same as the vapor pressure of pure water, which is 12.3 kPa. Therefore, the correct answer is option a) 12.3 kPa.