Synthesis and Purification of Acetanilide by Recrystallization PDF

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Synthesis and Purification of Acetanilide by Recrystallization. Extremely good lab report....

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Experiment #3 Synthesis and Purification of Acetanilide by Recrystallization Dawson College, Department of Chemistry and Chemical Technology Organic Chemistry, 202-BZF-05, section 00010, fall semester, 2021

Amine Ouachani, 2034815

Procedure Refer to laboratory manual

Sample calculations 1) Moles of aniline used :

Mass of aniline weighed =0.1751 g Molar mass of aniline =

93.13 g mole

Moles of aniline=0.1751 g ⋅

1 mole =0.0019 ( 0.001880167 ) ( 93.13 g)

2) Mass of acetic anhydride used :

Volume of acetic anhydride used=0.300 mL Density of acetic anhydride=1.08

g mL

(

Mass of acetic anhydride used =0.300 mL⋅ 1.08

)

g =0.324 g mL

3) Moles of acetic anhydride used : See calculation 1, same principle but with 0.324 grams of acetic anhydride as well as the molar mass of acetic anhydride instead (102.09 g/mol). 4) Determination of the limiting reactant : The reaction is :

Moles of aniline=0.0019 Moles of acetic anhydride=0.0032 The limiting reactant is determined by dividing the number of moles present of each reactant by its coefficient. The one with the smallest number is the limiting reactant. So,

Aniline :

0.0019 =0.0019 1

Acetic Anhydride :

0.0032 =0.0032 1

Aniline is the limiting reactant.

5) Theoretical moles of acetanilide : The reaction is :

Using the limiting reactant, we get :

1 mole of Acetanilide 1mole of Aniline = x 0.0019moles of Aniline Using stoichiometry :

x=

0.0019 moles of aniline⋅1 mole of Acetanilide =0.0019 moles of Acetanilide 1 mole of Aniline

6) Theoretical mass of acetanilide :

Molar mass of acetanilide=135.16

g mole

Moles of acetanilide=0.0019 Theoretical mass of acetanilide=0.0019 moles⋅

g =0.2568 g (135.16 1 mole )

7) Percent yield of the reaction :

Actual mass of acetinilide obtained=0.0743 g Theoretical mass of acetanilide=0.2568 g

Percent yield=

Actual Mass of acetinilide obtained 0.0743 g = =28.9 % Theoretical mass of acetanilide 0.2568 g

Answers to Questions 1. Show the percent yield calculation.

Actual mass of acetinilideobtained=0.0743 g Theoretical mass of acetanilide =0.2568 g Percent yield=

Actual Mass of acetinilide obtained 0.0743 g = =28.9 % Theoretical mass of acetanilide 0.2568 g

2. Referring to the data obtained from the experiment, explain whether your synthesis and purification of acetanilide was successful or not. Our synthesis of acetanilide was unsuccessful since we only obtained 0.0743 grams of acetanilide, compared to the theoretical value of 0.2568 grams of acetanilide that we should have obtained. This gives us a percent yield of only 28.9%. Considering the fact that the greater the percent yield, the closer the actual value to the theoretical one, our low percent yield indicates that we should have had way more acetanilide synthesized. However, our purification of acetanilide was quite successful since our experimental melting point of pure acetanilide was 114-115 °C, which is the exact literature value of the melting point of acetanilide....