Tara Ghaemi 9/16/16
Chao Li 232
Recrystallization of Acetanilide
Introduction
In this experiment, acetanilide will be purified to remove its two impurities by utilizing dissolution, hot vacuum filtration, and recrystallization. Hot vacuum filtration is performed to separate the crystal from the solution that it is present in. Hot vacuum filtration works best for this experiment because it prevents the premature crystallization of the solute, and thus lets the extracted crystal be extremely pure. For hot vacuum filtration to be used, impurity A must be less soluble than impurity B. Hot vacuum filtration allows for the more insoluble of the two impurities to be removed and thus, impurity A must also be less soluble than acetanilide in order …show more content…
Reagents and Products
Reagent(s) and Product(s) Equivalents (Theoretical) MW (g/mol) Moles
(Theoretical) Theoretical weight and/or volume Actual weight or volume (and % yield for product)
Acetanilide
_____ 135.160 .00148 mols 0.2 g 0.24 g, 19.4 % yield for product
Table 2. Observations
Action Observed Change
Initial Boiling Dissolution of solute, some solute still remains
Full dilution of solute Contents of test tube appear to be a cloudy liquid
Initial Filtration and Vacuum Crystals with a light brown tint appear
Second Filtration and Vacuum Crystals still have a light brown tint, albeit less than that seen at initial filtration
Table 3. Spectroscopic data
Purity of Acetanilide Melting Point
Crude 84°-93° C
Purified 95°-100° C
Calculations.
% product recovery=(final amount of product)/(initial amount of product) × 100%
% yield= (.043 g)/(.248 g)× 100%=19.4% product …show more content…
Once again, this signifies impurities present in the acetanilide crystals. However, if performed correctly, recrystallization would have been a very efficient way of obtaining the pure acetanilide from the solution with the more soluble of the two impurities. Additionally, the melting point for the recovered acetanilide was 95°-100° C, while the actual melting point for pure acetanilide is 114.3° C. This difference in melting point clearly points to impurity still existing in the recovered product. Additionally, the 5° C range of melting point further suggests impurity in the final product as pure products generally only have a range of 2°
Chao Li 232
Recrystallization of Acetanilide
Introduction
In this experiment, acetanilide will be purified to remove its two impurities by utilizing dissolution, hot vacuum filtration, and recrystallization. Hot vacuum filtration is performed to separate the crystal from the solution that it is present in. Hot vacuum filtration works best for this experiment because it prevents the premature crystallization of the solute, and thus lets the extracted crystal be extremely pure. For hot vacuum filtration to be used, impurity A must be less soluble than impurity B. Hot vacuum filtration allows for the more insoluble of the two impurities to be removed and thus, impurity A must also be less soluble than acetanilide in order …show more content…
Reagents and Products
Reagent(s) and Product(s) Equivalents (Theoretical) MW (g/mol) Moles
(Theoretical) Theoretical weight and/or volume Actual weight or volume (and % yield for product)
Acetanilide
_____ 135.160 .00148 mols 0.2 g 0.24 g, 19.4 % yield for product
Table 2. Observations
Action Observed Change
Initial Boiling Dissolution of solute, some solute still remains
Full dilution of solute Contents of test tube appear to be a cloudy liquid
Initial Filtration and Vacuum Crystals with a light brown tint appear
Second Filtration and Vacuum Crystals still have a light brown tint, albeit less than that seen at initial filtration
Table 3. Spectroscopic data
Purity of Acetanilide Melting Point
Crude 84°-93° C
Purified 95°-100° C
Calculations.
% product recovery=(final amount of product)/(initial amount of product) × 100%
% yield= (.043 g)/(.248 g)× 100%=19.4% product …show more content…
Once again, this signifies impurities present in the acetanilide crystals. However, if performed correctly, recrystallization would have been a very efficient way of obtaining the pure acetanilide from the solution with the more soluble of the two impurities. Additionally, the melting point for the recovered acetanilide was 95°-100° C, while the actual melting point for pure acetanilide is 114.3° C. This difference in melting point clearly points to impurity still existing in the recovered product. Additionally, the 5° C range of melting point further suggests impurity in the final product as pure products generally only have a range of 2°