If the same solute is dissolved in two different solvents to the same concentration and the same temperature, the osmotic pressure ____
will be the same for both.
will be different.
may be the same or different, depending on the solute.
will be lower in the solvent with higher molecular weight.
I don't understand how the colligative properties will vary by solvent through the equation pi=iMRT. Isn't the molarity calculated through moles of solute/ "L of solvent"? However, in reality, this is physically impossible. I think it is the fourth choice, simply because higher molecular weight will cause lower moles of solvent.
If i, M, R, and T are the same, how can pi be any different? However, the problem doesn't state that i is the same; only that the two solvents are different. So how pi varies will depend upon how the solute and solvent interact (how i changes) and that isn't one of the choices. I would pick "none of the above" if given the choice.
The osmotic pressure in a solution is determined by the concentration of the solute particles, as well as the temperature. According to the van't Hoff equation, the osmotic pressure (pi) is given by the equation pi = iMRT, where i is the van't Hoff factor (the number of particles produced per molecule of solute in solution), M is the molarity of the solute, R is the gas constant, and T is the absolute temperature.
In this scenario, if the same solute is dissolved in two different solvents to the same concentration and at the same temperature, the molarity (M) will be the same for both solutions. This is because the concentration of the solute remains constant, regardless of the solvent.
Therefore, based on the van't Hoff equation, the osmotic pressure would be the same for both solutions, assuming all other factors remain constant. So, the correct answer is the first option: the osmotic pressure will be the same for both solutions.
Regarding your confusion about the molarity calculation, you are correct that molarity is calculated using moles of solute divided by the volume of solvent (in liters). However, in this particular case, we're assuming that the same amount of solute is dissolved in both solvents to obtain the same concentration. So, the molarity would be the same for both solutions.