.070g caffeine dissolved in 4 mL water. caffeine is extracted from aqueous solution 3 times with 2mL portions of methylene chloride. calculate total amount of caffeine that can be extracted into the 3 portions. caffeine has a distribution coefficient of 4.6 between methylene chloride and water
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To calculate the total amount of caffeine that can be extracted into the three portions of methylene chloride, we need to consider the distribution coefficient and the initial amount of caffeine dissolved in water.
Given:
Initial amount of caffeine dissolved in water = 0.070 g
Distribution coefficient (D) = 4.6
Volume of each methylene chloride portion = 2 mL
We'll calculate the amount of caffeine extracted in each portion and add them up to find the total amount.
Step 1: Calculate the amount of caffeine in the first portion of methylene chloride.
Amount of caffeine in the first portion = Initial amount * D
= 0.070 g * 4.6
= 0.322 g
Step 2: Calculate the amount of caffeine in the second portion of methylene chloride.
Amount of caffeine in the second portion = (Initial amount - amount in the first portion) * D
= (0.070 g - 0.322 g) * 4.6
= 0 g (Since we cannot extract a negative amount)
Step 3: Calculate the amount of caffeine in the third portion of methylene chloride.
Amount of caffeine in the third portion = (Initial amount - amount in the first portion - amount in the second portion) * D
= (0.070 g - 0.322 g - 0 g) * 4.6
= 0 g (Since we cannot extract a negative amount)
Step 4: Calculate the total amount of caffeine extracted into the three portions.
Total amount of caffeine extracted = amount in the first portion + amount in the second portion + amount in the third portion
= 0.322 g + 0 g + 0 g
= 0.322 g
Therefore, the total amount of caffeine that can be extracted into the three portions of methylene chloride is 0.322 grams.
To calculate the total amount of caffeine that can be extracted into the three portions of methylene chloride, we need to consider the distribution coefficient and the initial amount of caffeine dissolved in water.
First, let's calculate the amount of caffeine that can be extracted in the first portion of methylene chloride. Since caffeine has a distribution coefficient of 4.6 between methylene chloride and water, we can calculate the amount of caffeine extracted using the following formula:
Amount of Caffeine Extracted = Distribution Coefficient x Amount of Caffeine in Water
Amount of Caffeine Extracted in the first portion = 4.6 x 0.070 g
Next, we'll calculate the amount of caffeine remaining in the water after the first extraction. Since we started with 0.070 g of caffeine and extracted a certain amount, the caffeine remaining is:
Caffeine Remaining in Water after the first extraction = Initial Amount - Amount Extracted in the first portion
= 0.070 g - (4.6 x 0.070 g)
Now, we'll repeat the extraction process two more times using the remaining caffeine in the water after each extraction. The amount of caffeine extracted in the second and third portions of methylene chloride can be calculated using the same formula:
Amount of Caffeine Extracted in each portion = Distribution Coefficient x Caffeine Remaining in Water
Amount of Caffeine Extracted in the second portion = 4.6 x (Caffeine Remaining in Water after the first extraction)
Amount of Caffeine Extracted in the third portion = 4.6 x (Caffeine Remaining in Water after the second extraction)
Finally, we can calculate the total amount of caffeine that can be extracted into the three portions by summing up the amounts extracted in each portion:
Total Amount of Caffeine Extracted = Amount Extracted in the first portion + Amount Extracted in the second portion + Amount Extracted in the third portion
Total Amount of Caffeine Extracted = (4.6 x 0.070 g) + (4.6 x (Caffeine Remaining in Water after the first extraction)) + (4.6 x (Caffeine Remaining in Water after the second extraction))
Please note that to obtain the exact value of the total amount of caffeine extracted, you need to substitute the values of "Caffeine Remaining in Water after the first extraction" and "Caffeine Remaining in Water after the second extraction" obtained in the calculations.