A 5 μL drop of compound X, a 7 μL drop of compound Y, and a 15 μL of compound Z are placed in a closed container with 5 mL water and 2.5 mL air. The system is equilibrated at 25°C. Determine the fraction of the total X, Y, and Z mass associated with each of the 3 phases: water, air, and non-aqueous.
To determine the fraction of the total X, Y, and Z mass associated with each of the three phases (water, air, and non-aqueous), we need to consider the properties of the compounds and the distribution of these compounds between the different phases.
First, let's determine the total mass of each compound:
Mass of compound X = 5 μL
Mass of compound Y = 7 μL
Mass of compound Z = 15 μL
Since the density of water is approximately 1 g/mL, we can convert the volumes of compounds X, Y, and Z to mass:
Mass of compound X = 5 μL * 1 g/mL = 5 mg
Mass of compound Y = 7 μL * 1 g/mL = 7 mg
Mass of compound Z = 15 μL * 1 g/mL = 15 mg
Now, let's consider the distribution of these compounds between the phases:
1. Water Phase:
The water phase consists of 5 mL of water. To determine the fraction of the total mass of each compound associated with water, we need to calculate the solubility of each compound in water.
Let's assume that compound X is completely soluble in water. Therefore, the entire mass of compound X (5 mg) will be associated with the water phase.
For compound Y, let's assume it has a solubility of 50% in water. This means that 50% of the mass of compound Y (7 mg) will be associated with the water phase. So, 50% of 7 mg = 3.5 mg of compound Y will be associated with the water phase.
Similarly, let's assume compound Z has a solubility of 20% in water. This means that 20% of the mass of compound Z (15 mg) will be associated with the water phase. So, 20% of 15 mg = 3 mg of compound Z will be associated with the water phase.
2. Air Phase:
The air phase consists of 2.5 mL of air. Compounds X, Y, and Z are likely to have very low solubility in air, so we can assume that none of their mass will be associated with the air phase.
3. Non-aqueous Phase:
The non-aqueous phase consists of the remaining volume of the container, which is the difference between the total volume of the system (5 mL water + 2.5 mL air = 7.5 mL) and the volumes of the aqueous phases (5 mL water). Therefore, the volume of the non-aqueous phase is 2.5 mL (7.5 mL - 5 mL).
Since compounds X, Y, and Z are not water-soluble, it is reasonable to assume that their entire masses will be associated with the non-aqueous phase.
So, to summarize the fraction of the total mass associated with each phase:
Water phase:
- Compound X: 100% (5 mg)
- Compound Y: 50% (3.5 mg)
- Compound Z: 20% (3 mg)
Air phase: 0%
Non-aqueous phase:
- Compound X: 0% (0 mg)
- Compound Y: 50% (3.5 mg)
- Compound Z: 80% (12 mg)
Note that these assumptions and calculations are based on the given information and general knowledge about solubility. The actual distribution of compounds between phases can vary depending on factors such as temperature, pressure, and the nature of the compounds themselves.