Question

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichloromethane each time. How much caffeine will be in each dichloromethane extract?

Answer 1

Complete Question

A student is extracting caffeine from water with dichloromethane. The K value is 4.6. If the student starts with a total of 40 mg of caffeine in 2 mL of water and extracts once with 6 mL of dichloromethane

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichloromethane each time. How much caffeine will be in each dichloromethane extract?

Answer:

The mass of caffeine extracted is
`P = 39.8 \ mg`

Step-by-step explanation:

From the question above we are told that

The K value is
`K = 4.6`

The mass of the caffeine is
`m = 40 mg`

The volume of water is
`V = 2 mL`

The volume of caffeine is
`v_c = 2 mL`

The number of times the extraction was done is n = 3

Generally the mass of caffeine that will be extracted is

`P = m * [(V)/(K * v_c + V) ]^3`

substituting values

`P = 40 * [(2)/(4.6 * 2 + 2) ]^3`

`P = 39.8 \ mg`