When 200 mL of an aqueous benzoic acid solution were extracted with 30 mL of ethyl actetate 45% of the benzoic acid were extracted. Calculate the partition coefficient of benzoic acid.
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But onto your question! The partition coefficient (P) is calculated by dividing the concentration of benzoic acid in the organic phase (ethyl acetate) by the concentration of benzoic acid in the aqueous phase. Since you've told me that 45% of the benzoic acid was extracted, we can calculate the partition coefficient as follows:
P = [benzoic acid] in ethyl acetate / [benzoic acid] in aqueous phase
P = 0.45 / 0.55
P ≈ 0.82
So, the partition coefficient of the benzoic acid is approximately 0.82. Keep in mind that this value represents the relative affinity of the benzoic acid for the organic phase (ethyl acetate) versus the aqueous phase.
To calculate the partition coefficient of benzoic acid, we first need to understand what the partition coefficient represents. The partition coefficient, often denoted as P, is a measure of how a solute distributes or partitions itself between two immiscible phases, in this case, between an aqueous phase and an organic phase. It is defined as the ratio of the concentration of the solute in one phase to its concentration in the other phase at equilibrium.
In this problem, benzoic acid is being extracted from an aqueous phase into an organic phase (ethyl acetate). We are given that 45% of the benzoic acid is extracted, which means that 45% of the original amount of benzoic acid in the aqueous phase is now in the organic phase.
Now, let's calculate the partition coefficient using the given information:
1. Calculate the concentration of benzoic acid in the aqueous phase:
- Initial concentration = V1 x C1, where V1 is the volume of the aqueous phase (200 mL) and C1 is the original concentration of benzoic acid.
2. Calculate the concentration of benzoic acid in the organic phase:
- Extracted amount = 45% of the initial concentration = 0.45 x (V1 x C1)
- Final concentration in the organic phase = Extracted amount / V2, where V2 is the volume of the organic phase (30 mL).
3. Calculate the partition coefficient (P):
- P = (Final concentration in the organic phase) / (Concentration in the aqueous phase)
Note: Make sure to use consistent unit measurements (e.g., mL or L) for volume and (mol/L) for concentration to obtain correct results.
By following these steps and plugging in the given values, you can calculate the partition coefficient of benzoic acid.