The distribution coefficient between ether and water for aspirin at room temperature is 3.5. What weight of aspirin would be extracted by a single extraction with 60 ml of water from a solution of 10 grams of aspirin in 100 ml of ether? Calculate the weight of aspirin which would be removed by three extractions with 20 ml portions of water.

Ko/d = (org layer)/(aq layer)

K = 3.5
Let x = wt in aq layer
Then 10-x = wt in org layer

3.5 = (10-x)/(100)/(x/60)
Solve for x

Do that three times for 3 extractions.

To calculate the weight of aspirin extracted in a single extraction, we can use the formula:

Weight of aspirin extracted = (Distribution coefficient) x (Weight of aspirin in ether) / (Volume of water)

Given:

- Distribution coefficient (D) = 3.5
- Weight of aspirin in ether = 10 grams
- Volume of water = 60 ml

Applying the formula, we get:

Weight of aspirin extracted in a single extraction = (3.5) x (10 grams) / (60 ml)
Weight of aspirin extracted in a single extraction = 0.5833 grams

Therefore, in a single extraction with 60 ml of water, approximately 0.5833 grams of aspirin would be extracted.

Now, to calculate the weight of aspirin removed by three extractions with 20 ml portions of water, we can employ the same formula, but repeat the calculations three times.

Taking the weight of aspirin in ether as 10 grams and dividing it into three equal portions (10 grams / 3), each portion will contain approximately 3.3333 grams of aspirin.

Weight of aspirin extracted in the first extraction = (3.5) x (3.3333 grams) / (20 ml)
Weight of aspirin extracted in the first extraction = 0.5833 grams

Weight of aspirin remaining in ether after the first extraction = 3.3333 grams - 0.5833 grams
Weight of aspirin remaining in ether after the first extraction = 2.7500 grams

In the second extraction, we repeat the calculations with the remaining 2.7500 grams of aspirin in ether:

Weight of aspirin extracted in the second extraction = (3.5) x (2.7500 grams) / (20 ml)
Weight of aspirin extracted in the second extraction = 0.4792 grams

Weight of aspirin remaining in ether after the second extraction = 2.7500 grams - 0.4792 grams
Weight of aspirin remaining in ether after the second extraction = 2.2708 grams

Finally, in the third extraction, we use the remaining 2.2708 grams of aspirin:

Weight of aspirin extracted in the third extraction = (3.5) x (2.2708 grams) / (20 ml)
Weight of aspirin extracted in the third extraction = 0.3958 grams

Adding up the amounts of aspirin extracted in each extraction:

Total weight of aspirin extracted in three extractions = 0.5833 grams + 0.4792 grams + 0.3958 grams
Total weight of aspirin extracted in three extractions = 1.4583 grams

Therefore, by performing three extractions with 20 ml portions of water, approximately 1.4583 grams of aspirin would be removed.

To calculate the weight of aspirin that would be extracted, we need to understand the concept of distribution coefficient and how it relates to the extraction process.

The distribution coefficient (K_d) is defined as the ratio of the concentration of a solute in one solvent phase to its concentration in another solvent phase at equilibrium. In this case, K_d represents the ratio of the concentration of aspirin in ether to its concentration in water.

For the first part of the question, we are given that the distribution coefficient between ether and water for aspirin is 3.5. This means that, at equilibrium, the concentration of aspirin in ether is 3.5 times higher than its concentration in water.

To calculate the weight of aspirin extracted by a single extraction with 60 ml of water, we can use the following formula:

Weight of aspirin extracted = (Concentration of aspirin in water) x (Volume of water)

However, as we don't know the concentration of aspirin in water, we need to calculate it using the distribution coefficient. Since we are given the initial concentration of aspirin in ether, we can use it to find the concentration in water.

Concentration of aspirin in water = (Concentration of aspirin in ether) / (Distribution coefficient)

Let's calculate it:

Concentration of aspirin in water = (10 grams/100 ml) / 3.5
= 0.1 grams/ml / 3.5
= 0.02857 grams/ml

Now we can calculate the weight of aspirin extracted:

Weight of aspirin extracted = (0.02857 grams/ml) x (60 ml)
= 1.714 grams

Therefore, a single extraction with 60 ml of water would extract 1.714 grams of aspirin.

Moving on to the second part of the question, where three extractions with 20 ml portions of water are used, we can apply the same procedure to calculate the weight of aspirin removed.

Weight of aspirin removed after each extraction = (0.02857 grams/ml) x (20 ml)
= 0.5714 grams

Since there are three extractions, we need to multiply the weight removed after each extraction by 3:

Weight of aspirin removed by three extractions = 0.5714 grams/extraction x 3 extractions
= 1.714 grams

So, by using three extractions with 20 ml of water each, the weight of aspirin removed would be 1.714 grams, which is the same as in the single extraction with 60 ml of water.