The solubility of acetanilide is 3.53 g in 100 mL of chloroform at 0 °C, and 29.1 g in 100 mL of chloroform at 60 °C. What is the maximum percent recovery that can be achieved for the recrystallization of acetanilide from chloroform?
Hint: During a recrystallization, some of the acetanilide stays in solution. The percent recovery expresses the ratio of pure material to crude starting material as a percentage.
You can make the problem easier by choosing to dissolve 29.1 g acetanilide in 100 mL solvent at 60 C.
Then you cool it to O c and it will dissolve 3.53g. How much do you recover?
That's 29.1-3.53 = ? grams recovered.
What percent is that?
That's (?g/29.1)*100 = ?%
87.9%
To calculate the maximum percent recovery that can be achieved for the recrystallization of acetanilide from chloroform, we need to find the amount of pure material that can be recovered.
Step 1: Calculate the amount of acetanilide recovered at each temperature.
At 0 °C: The solubility of acetanilide is 3.53 g in 100 mL of chloroform.
So, at 0 °C, we have 3.53 g of acetanilide recovered in 100 mL of chloroform.
At 60 °C: The solubility of acetanilide is 29.1 g in 100 mL of chloroform.
So, at 60 °C, we have 29.1 g of acetanilide recovered in 100 mL of chloroform.
Step 2: Calculate the maximum amount of acetanilide that can be recovered.
The maximum amount of acetanilide that can be recovered is the lower value of the two solubilities because that represents the limiting factor.
Comparing the solubilities, 3.53 g is smaller than 29.1 g, so we consider 3.53 g as the maximum amount that can be recovered.
Step 3: Calculate the maximum percent recovery.
To calculate the percent recovery, we need to compare the amount of pure material to the amount in the crude starting material.
The percent recovery can be calculated using the formula:
Percent recovery = (Amount of pure material / Amount in crude starting material) × 100
In this case, the amount of pure material is 3.53 g, and the amount in the crude starting material is unknown.
Let's assume the amount in the crude starting material is represented by 'X' g.
Using the formula, we have:
Percent recovery = (3.53 g / X g) × 100
Since we are calculating the maximum percent recovery, the amount in the crude starting material will be the maximum amount that can be recovered, which is 3.53 g.
Substituting the values, we have:
Percent recovery = (3.53 g / 3.53 g) × 100
Percent recovery = 100%
Therefore, the maximum percent recovery that can be achieved for the recrystallization of acetanilide from chloroform is 100%.
To find the maximum percent recovery that can be achieved for the recrystallization of acetanilide from chloroform, we need to compare the amount of acetanilide dissolved at 0 °C with the amount dissolved at 60 °C.
First, we need to calculate the amount of acetanilide dissolved in grams at each temperature. We have the following information:
- At 0 °C: 3.53 g of acetanilide is dissolved in 100 mL of chloroform.
- At 60 °C: 29.1 g of acetanilide is dissolved in 100 mL of chloroform.
Now, we can calculate the maximum amount of acetanilide that can be recovered at each temperature.
At 0 °C:
If 3.53 g of acetanilide is dissolved in 100 mL of chloroform, the total amount of acetanilide in the solution is 3.53 g. This is our starting amount.
At 60 °C:
If 29.1 g of acetanilide is dissolved in 100 mL of chloroform, the total amount of acetanilide in the solution is 29.1 g. This is our maximum possible recovery.
To calculate the percent recovery, we divide the maximum possible recovery (29.1 g) by the starting amount (3.53 g), and multiply by 100 to convert it to a percentage:
Percent recovery = (29.1 g / 3.53 g) * 100 = 824.5%
Therefore, the maximum percent recovery that can be achieved for the recrystallization of acetanilide from chloroform is 824.5%. This means that if the recrystallization process is carried out perfectly, we can recover up to 824.5% of the pure acetanilide from the crude starting material.
Note: It is important to note that this value exceeds 100% because during the recrystallization process, impurities may be removed from the crude material, resulting in a higher percentage recovery.