*Please note my question is found in the Analysis section of this Lab.
Preparation of Esters
Instructions:
Carry out the virtual lab as outlined below. You will need to record your data in an observations table of your design. When you have completed the lab, word process it – include your observation table (with all observations), analysis and answers to questions.
Purpose:
The purpose of this lab is to determine what combinations of alcohols and carboxylic acids make the scents wintergreen, pineapple and rum.
Materials:
methanol
conc. H2SO4 in a dropper bottle
hot plate
ethanol
test tube
500 mL beaker
butanoic acid
10 mL transfer pipet
timer
methanoic acid
pipet bulb
salicylic acid
distilled water
Procedure:
1. Prepare a hot water bath by half-filling a 500 mL beaker with water and heating it gently on a hot plate until it comes to a boil
2. Using a transfer pipet, place 2 mL of an alcohol into a test tube. (In the virtual lab, click on the pipet and dip it into either the methanol or ethanol beaker. Then click on the pipet to fill it. Move it over to the empty test tube and click once for each 1mL. TIP: On the second click for the second 1 mL, hold down the click and move the pipet to the side and empty it so it is ready to fill with the next liquid.)
3. Using a transfer pipet, place 2 mL of an acid into the test tube.
4. Add 2 mL of sulfuric acid to the test tube.
5. Place in the water bath for 5 minutes. (To place in the water bath, click on the hot plate at the top right and you will be taken to another screen where you will see your test tube in a hot water bath on the hot plate. Press the red button on the hot plate and you will see the clock go forward 5 minutes. You may see changes in the test tube or you may not. The colour in the test tube corresponds to the colour scale on screen. Wintergreen – Green, Pineapple – Yellow, Brown – Rum)
6. Record the scent (if present) into an observations table. If no scent is detected, it must also be recorded.
7. Repeat steps 1-5 until the three scents have been identified.
Here are the results I got from my lab experiment at school today.
Methanol + Butanoic acid + Sulfuric acid = pineapple
Methanol + Salicylic acid + Sulfuric acid = wintergreen
Ethanol + Methanoic acid + Sulfuric acid = rum
Analysis:
Write chemical equations using diagrams or chemical formulae to represent each of the three esterification reactions that resulted in the three scents.
I will rewrite the lab since it doesnt seem to work through the copy-and-paste method
*Please note my question is found in the Analysis part of this lab.
Preperation of Esters
Instructions:
Carry out the virtual lab as outlined below. You will need to recorde your data in an observations table of your design. When you have completed the lab, word process it - include your observation table (with all observations), analysis and answers to questions.
Purpose:
The purpose of this lab is to determine what combinations of alcohols and carboxylic acids, make the scents wintergreen, pineapple and rum.
Materials:
methanol
conc.H2SO4 in a dropper bottle
hot plate
ethanol
test tube
500 mL beaker
butanoic acid
10 mL transfer pipet
timer
methanoic acid
pipet bulb
salicylic acid
distilled water
Procedure:
Prepare a hot water bath by half-filling a 500 mL beaker with water and heating it gently on a hot plate until it comes to a boil.
Using a transfer pipet, place 2 mL of an alcohol into a test tube.
Using a transfer pipet, place 2 mL of an acid into the test tube.
Add 2 mL of sulfuric acid to the test tube.
Place in the water bath for 5 minutes.
You may see changes in the test tube or you may not. The colour in the test tube corresponds to the colour scale on screen. Wintergreen - Green, Pineapple - Yellow, Brown - Rum)
Record the scent (if present) into an observations table.
Repeat steps 1-5 until the three scents have been identified.
My observations
Methanol - Butanoic acid – Sulfuric acid = pineapple
Methanol – Salicylic acid– Sulfuric acid = wintergreen
Ethanol – Methanoic acid – Sulfuric acid = rum
Analysis:
Write chemical equations using chemical formulae to represent each of the three esterification reactions that resulted in the three scents.
I think you need to post a suggestion for the equations for us to work from. You could start by writing word equations for which you have the basis in your 'My observations' section. Remember that the acid is a catalyst here.
Methanol + Butanoic acid + Sulfuric acid = Pinapple
Methanol + Salicylic acid + Sulfuric acid = wintergreen
Ethanol + Methanoic acid + Sulfuric acid = rum
To write the chemical equations for the three esterification reactions, we need to understand the esterification process. During esterification, an alcohol reacts with a carboxylic acid in the presence of an acid catalyst, such as sulfuric acid. This reaction results in the formation of an ester and water.
1. Methanol + Butanoic acid + Sulfuric acid = pineapple scent:
The chemical equation for this reaction can be written as:
CH3OH + CH3CH2CH2CH2COOH + H2SO4 → CH3CH2CH2CH2COOCH3 (Butyl methanoate) + H2O
2. Methanol + Salicylic acid + Sulfuric acid = wintergreen scent:
The chemical equation for this reaction can be written as:
CH3OH + C6H4(OH)COOH + H2SO4 → C6H4(OH)3 (Methyl salicylate) + H2O
3. Ethanol + Methanoic acid + Sulfuric acid = rum scent:
The chemical equation for this reaction can be written as:
CH3CH2OH + HCOOH + H2SO4 → CH3CH2COOCH3 (Ethyl methanoate) + H2O
Each equation represents the esterification between the alcohol and carboxylic acid, resulting in the formation of the specific ester responsible for the corresponding scent: butyl methanoate for pineapple, methyl salicylate for wintergreen, and ethyl methanoate for rum.