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 
Explanation:
From the question above we are told that
The K value is 
The mass of the caffeine is 
The volume of water is 
The volume of caffeine is 
The number of times the extraction was done is n = 3
Generally the mass of caffeine that will be extracted is
![P = m * [\frac{V}{K * v_c + V} ]^3](https://tex.z-dn.net/?f=P%20%3D%20%20m%20%20%2A%20%20%5B%5Cfrac%7BV%7D%7BK%20%2A%20%20v_c%20%2B%20V%7D%20%5D%5E3)
substituting values
![P = 40 * [\frac{2}{4.6 * 2 + 2} ]^3](https://tex.z-dn.net/?f=P%20%3D%20%2040%20%20%20%2A%20%20%5B%5Cfrac%7B2%7D%7B4.6%20%2A%20%202%20%2B%202%7D%20%5D%5E3)
A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable. This is important for processes and/or reactions which require specific and stable pH ranges. Buffer solutions have a working pH range and capacity which dictate how much acid/base can be neutralized before pH changes, and the amount by which it will change.
Is A “the density of the ice decreased as it melted”
The characteristics of wave are amplitude, speed , frequency and wavelength.
<u>Explanation:</u>
Amplitude is defined as the distance covered by the particles or molecules moving in a wave nature. So the maximum positive and negative peak position is termed as amplitude of the wave.
Every wave forms a series of crests and trough regions. The crest region is the positive amplitude while the trough region is the negative amplitude. The distance between two successive crests and troughs are termed as wavelength.
A single crest and trough forms a complete cycle. So the number of times a cycle is repeated for a given time is known as frequency. Speed is defined as the product of frequency and wavelength of the wave. In other words, speed of a wave is the rate at which the particles are moving a given area per unit time.
