extraction Flashcards
In this experiment, you will be using both an acid solution and a base solution. To extract an acid from a mixture into an aqueous solution and then recover it from the aqueous solution-
A. You will add an acid solution in the first part to extract and then use base to recover the acid.
B. You will add a base solution in the first part to extract and then use acid to recover the acid.
B. You will add a base solution in the first part to extract and then use acid to recover the acid.
True or false? During the extraction process when you have both organic and aqueous solutions in immiscible layers, the naphthalene will be in the organic layer.
True
False
True
How will you recover the naphthalene from its solution at the end of the extraction?
By adding an acid to the solution
Filter the product
Evaporate the solvent
By adding water to the solution
Evaporate the solvent
True or False? During the extraction procedure, the organic layer will be on the top layer.
True
false
true
In your extraction, the organic layer will mainly be the organic solvent. What organic solvent will you use?
Dichloromethane
Sodium hydroxide
Diethyl ether
Chloroform
Diethyl ether
Benzoic acid (an organic acid) is soluble in which of the following organic solvents?
Diethyl ether
Water
Sodium hydroxide (NaOH 6M)
All of the above!
Diethyl ether
Benzoic acid (an organic acid) is soluble in which of the following organic solvents?
Diethyl ether
Water
Sodium hydroxide (NaOH 6M)
All of the above!
Diethyl ether
what is the equation for percent recover
(combined weight of the isolated compounds/weight of the starting mixture) x 100
Your recovery is highly unlikely to be exactly 100%. Which of the following are possible reasons why your recovery is less than 100%?
Mechanical losses (e.g. during transfers)
Incomplete deprotonation
Incomplete reprotonation
All of the above are possible reasons!
All of the above are possible reasons!
Suppose, after extraction, you did not allow enough time for the recovered benzoic acid to dry. Therefore, it was still wet when you measured its weight and calculated the percent recovery. Which of the following do you think might be your value for percent recovery?
<100%
>100%
Cannot be determined. Need more information.
> 100%
Suppose, the melting point of a certain compound is observed to be have a narrow range (1-3 oC) and matches to the literature range for that compound.
What will be your conclusion about the purity of the compound?
Pure
Impure
pure
what is the polarity of carbon tetrachloride
non polar
what is the polarity of water
polar protic
what is the polarity of diethyl either
polar aprotic
what is the polarity of acetone
polar aprotic
unable to form hydrogen bonds a
what is the polarity of methanol
polar protic
polar solvents that have at least 1 hydrogen that is connected directly to a particular electronegative atom such as O-H, N-H,,
What are the TWO most important IMFs between sodium sulfate and water
ion-dipole forces and hydrogen bonding
After extraction of the benzoic acid into the aqueous solution as its anionic salt, the ether solution was then washed with water two further times. What do you think was the purpose of these two wash steps?
To remove any remaining sodium hydroxide from the ether
To remove any remaining benzoic acid salt from the ether
To remove any remaining polar impurities from the ether
All of the above
All of the above
The ionized benzoic acid dissolves better in water than it does in diethyl ether, which is how and why it is extracted into the water phase. Give the TWO most important IMFs that are responsible for solubilizing the benzoic acid anion in the water
ion dipole forces and hydrogen bonding
As a follow-up to the previous question, give also the most important IMF that is responsible for solubilizing the sodium cation in the water.
ion dipole bonding
