Chem 108: Lab Simula on - chemconnections

Chem 108: Lab Simula1on

Aspirin Synthesis

https://www.youtube.com/watch?v=6lFQaxiRAmI

(Video includes recrystallization of crude aspirin with ethyl acetate, which is not part of the Lab Manual’s procedure, and

sulfuric acid is used in place of phosphoric acid)

https://forms.gle/XdLVP45QAtdP8RX18 _______________________

Experiment: Synthesis of an NSAID (Non-steroid anti-inflammatory drug)

Aspirin

http://chemconnections.org/general/movies/Representations.MOV

NSAIDs are used primarily to treat inflammation, mild to moderate pain, and fever.

C9H8O4

Synthesis of Aspirin (an NSAID)

Aspirin & Pain

Used primarily to treat inflammation, mild to moderate pain, and fever.

Representing Organic Molecules Common Formulas & Drawings

Molecular formula: Empirical Formula:

Bond-Line Structure:

C7H16O C7H16O

O

H

Condensed Structure:

Review: Lewis Structures & Molecular Modeling molview experiment (http://molview.org/)

Common Functional Groups

Name General Formula

Alcohols R-ΟΗ

Ethers R-Ο-Rʹ′

Amines R-ΝΗ2

Carboxylic Acids

R-C-OH

O

REACTANT: Salicylic Acid

Common Functional Groups

Name General Formula

Aldehydes

Ketones

Carboxylic Acids

Esters

Amides

R-C-OH

O

R-C-OR'

O

R-C-N

O

R

"

R

'

PRODUCT: Acetyl salicylic acid (Aspirin)

Synthesis of Aspirin

OOCCH3

COOH

CH3COCCH

3

O O

CH3COOH

OH

COOH

acetyl ester

acid

aspirin

++

alcohol (phenol)

acid

salicylic acidacetic

anhydride

ethanoic anhydride

acetic acid H3PO4

C7H6O3 C9H8O4

Synthesis of Aspirin

1.  Get equipment from stockroom with your group.

2.  Follow instructions in lab manual pg.88 carefully. Be mindful of your safety. WEAR eye protection.

3.  Store in lab drawer as instructed in Part A.3 of the instructions of the lab procedure.

4.  Part A-4. Next Week

H3PO4

(Pre-Covid-19): Lab Manual Procedure pp. 87-91; Data form (pg. 90 )

C7H6O3 C9H8O4

Vacuum Filtration

https://www.youtube.com/watch?v=uJO_frXdNsU

Part A.3 pg. 88 of the instructions of the lab procedure.

How many grams of aspirin can be produced from 5.0 g of salicylic acid reacting with an excess of acetic anhydride, C4H6O3 if everything is done perfectly in the experimental procedure?

QUESTION

OOCCH3

COOH

CH3COCCH

3

O O

CH3COOH

OH

COOH

acetyl ester

acid

aspirin

++

alcohol (phenol)

acid

salicylic acidacetic anhydride" acetic acid"

Mass Calculations: Reactants Products

!grams (Reactant) grams (Product)

grams (R)"

grams (R)" (Divide)""

Mass (R) by Molar"

1 mol (R)" grams (P)"

? grams (P)"

1 mol (P)"

Moles Molar Mass

? mol (P)"

? mol (R) "

"Gatekeepers”!from!Balanced reaction

Theoretical (Yield) Mass Calculations Reactant Product

(Multiply)""" Mass (P)"

by Molar"

Stoichiometry

!

5.0 grams (SA)"

grams (SA)" (Molecular Weight SA)"

1 mol (SA)"

grams (A)"

? (A)"

1 mol (A)"

(Molecular Weight A)"

Stoichiometry

1 mol A"

1 mol SA "

"Gatekeeper"

Mass Calculations:

C9H8O4 MW = 180.15

C7H6O3

MW = 138.12

grams (Aspirin) grams (Salicylic Acid) Moles Molar Mass

SA A

6.5 g aspirin

Answer

Percent Yield

 In synthesis as in any experiment, it is very difficult and at most times impossible to be perfect. Therefore the actual yield (g) is measured and compared to the theoretical calculated yield (g). This is the percent yield:

 % Yield = actual (g) / theoretical (g) x 100

1

QUESTION

 Kate’s synthesis of aspirin, C9H8O3, using acetic anhydride produced 5.90g. The calculated theoretical yield was 6.50g; what is her % yield?

A) 47.5% B) 80.3% C) 90.8% D) 110%

1

ANSWER

 Kate’s synthesis of aspirin, C9H8O3, produced 5.90g. The calculated theoretical yield was 6.50g; what is her % yield?

A) 47.5% B) 80.3% C) 90.8% D) 110%

1

5.90g / 6.50g X 100 =

Comparing Synthetic Procedures

 In synthesis as in any experiment, there are many different possible ways to produce the same product such as aspirin.

 Given those possible procedures & reactions, there are many things to consider in selecting which reaction and method is best, such as their relative safety, cost and yield compared to the other possible choices.

 % Yield = actual (g) / theoretical (g) x 100

1

!

5.0 grams (SA)"


1 mol (SA)"

grams (A)"

? (A)"

1 mol (A)"


Stoichiometry

1 mol A"

1 mol SA "

"Gatekeeper"

Different Synthetic Procedure:

C9H8O4 MW = 180.15

C7H6O3

MW = 138.12


SA A

Acetyl chloride"

6.5 g aspirin

Same theoretical amount, but different

reactant

QUESTION

 Gabe’s synthesis of aspirin, C9H8O3, using acetyl chloride produced 5.40g. The calculated theoretical yield was 6.50g; what is his % yield?

A) 47.5% B) 83.1% C) 90.8% D) 110%

1


Answer

 Gabe’s synthesis of aspirin, C9H8O3, using acetyl chloride produced 5.40g. The calculated theoretical yield was 6.50g; what is his % yield?

A) 47.5% B) 83.1% C) 90.8% D) 110%

1


5.40g / 6.50g X 100 =

QUESTION

Gabe’s synthesis of aspirin, C9H8O3, using acetyl chloride produced a different yield than Kate’s using acetic anhydride. If all other factors were equal, except for the difference in these two reactants, which would be the better choice Kate’s or Gabe’s? Briefly explain the reason for your choice, and provide one additional factor to consider such as by-products and waste beside percent yield.

1

Different Synthetic Procedures:

!

Aspirin Lab Manual Data Example:

OOCCH3

COOH

CH3COCCH

3

O O

CH3COOH

OH

COOH

acetyl ester

acid

aspirin

++

alcohol (phenol)

acid

salicylic acid

C9H8O4 C7H6O3

grams (Aspirin)"Theoretical grams (Salicylic Acid)

6.00 g 84.60 g

77.69g

acetic anhydride" acetic acid"

!

6.00 grams (SA)"


1 mol (SA)"

grams (A)"

? (A)"

1 mol (A)"


Stoichiometry

1 mol A"

1 mol SA "

"Gatekeeper"

Theoretical Yield Calculation:

C9H8O4 MW = 180.15

C7H6O3

MW = 138.12


SA A

7.83 g aspirin

!

Aspirin Lab Manual Data Example:

OOCCH3

COOH

CH3COCCH

3

O O

CH3COOH

OH

COOH

acetyl ester

acid

aspirin

++

alcohol (phenol)

acid

salicylic acid

C9H8O4 C7H6O3

grams (Aspirin)"Theoretical grams (Salicylic Acid) 7.83 g

7.83 g

6.00 g 84.60 g

% Yield = actual (g) / theoretical (g) x 100

% Yield = (6.91g) / (7.83 g) x 100 = 88.3%

77.69g

6.91 g

88.3 %

acetic anhydride" acetic acid"

Chem 108 Synthesis of Aspirin

Use pg. 90 as a working page for your individual data

Get individual data using your DVC ID & complete the table: http://chemconnections.org/general/chem108/Lab/RSC%20Aspirin/Aspirin-sim.codes.htm

Submit Completed Simulation & Report Questions https://forms.gle/XdLVP45QAtdP8RX18

http://www.rsc.org/learn-chemistry/resources/screen-experiment/aspirin/experiment/1

Optional Bonus

NOTE: Due to popularity & high web site traffic, access may be highly limited, very

difficult, & sporadic.


http://chemconnections.org/general/chem108/Lab/RSC%20Aspirin/RSC-aspirin-login.html Same user name & number for login as Titration, find here:

Only Aspirin level 1 is to be completed; the lab book then downloaded and submitted as an e-mail attachment.

Only Aspirin level 1 is to be completed; the lab book then downloaded and submitted as an e-mail attachment.



Same user name & number for login as Titration, find here:

http://chemconnections.org/general/chem108/Lab/RSC%20Aspirin/RSC-aspirin-login.html

Download log book and send as an e-mail attachment

log book (1,000 possible points)

Download log book and send as e-mail attachment. SEE Covid-19 Webpage for instructions.


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