Procedure :- A) Fischer Esterification 's Procedure ( Direct esterification of a carboxylic acid with an alcohol ):- 1- Choose any pair of these caboxylic acids and alcohols . When using excess alcohol, a molar ratio 4:1 is used in the procedure. 2- Mix 0.48 mol methanol with 0.12 mol butyric acid in a dry round bottom flask . 3- Add 0.05 moles of concentrated sulphuric acid to round bottom flask very slowly and carefully then put a magnetic stirrer . 4- Set up reflux system using a clean and dry condenser . 5- Place the flask on the hot plate and heat the reaction for 45 minutes - 1 hour . 6- When the reflux is over , remove magnetic stirrer and allow the reaction to cool to room temperature . 7- Add 20 ml of ice water to a separating funnel …show more content…
• it is a dehydrating agent ( allow the reaction to move forward towards ester formation ) . 2) The usage of dehydrating agents ( as CaCl or MgSo4) to remove excess water molecules trapped in the ester layer . B) Synthesis of ester using acetic anhydride :- 1- Add 2-3 ml of acetic anhydride in a large dry test tube then add 3 drops of concentrated sulphuric acid and mix. 2- Get any one of these alcohols (1-propanol, 3-methyl-1- butanol, benzyl alcohol, or 1-octanol) in a small dry test tube . 3- Put the large tube in an ice bath and start to add alcohol by an increasing rate . 4- Put the tube in hot water (70º C) for 5 minutes . 5- Add 8 drops of water with constant shaking then leave the reaction to cool to room temprature. 6- Add 6 mL of ( 3 mL saturated NaCl +3 mL distilled water) i.e : half-saturated sodium chloride solution to the test tube with vigorous shaking and then wait until two layers form (upper layer is ester while lower layer which consists of a water solution of sulfuric and acetic acids ,should be discarded …show more content…
8- Repeat step( 6 ). 9- Wash the ester layer with 6 ml saturated sodium chloride , shake and allow two layers to separate . At this point ,The ester layer should not be cloudy . Again discard lower layer. 10- Transfer the ester layer to a small dry test tube and dry the ester with anhydrous CaCl2 and stir for 10 min. 11- put it in a preweighed dry round bottom flask . 14- Determine the yield, refractive index, and % yield of ester. Conditions :- 1) This reaction is catalyzed by acid, Like Fischer esterification. 2) Usage of water in step (5):So that after Estrification is completed , any excess unreacted acetic anhydride is hydrolyzed. 3) The addition of half-saturated NaCl (in step 6): to help in separating the two layers. 4) The usage of a Base (step 7): to neutralize remaning acid . 5) Usage of concentrated sodium chloride in step (9):To dry the ester from any dissolved
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Describe the reaction. a. Observations: 6. Allow the product of the reaction to cool down for about a minute. 7. Use a pipette to add 2 of drops of water into test tube.
Chromatography Lab Riley Borklund Table 5, Seat 2A Lab Partners: Martin, Katherine, and Dakari Honors Biology, Mrs. Semaan January 5, 2016 Abstract: The purpose of this lab is to find what pigments are in a spinach leaf. The only pigments visible to the eye are chlorophyll a and chlorophyll b. We know this because chlorophyll reflects the green wavelength of light and shows us that it is present. We also, however, wanted to know what else is present in the spinach leaf.
Unknown compounds verification Introduction: In Project 3 we are going to test an unknown compound and there are several different ways that can help us to identify the Unknown substance. And there is some pre-lab information that found in the internet. By Experiment 3: Identification of a Substance by Physical Properties “Every substance has a unique set of properties that allow us to differentiate one from another. These properties can be classified as either physical properties or chemical properties.
Background Research: Isopods are group of small, cold-blooded, crustaceans also known as pillbugs and sowbugs (pillbugs are commonly known as “roly polies”). Pillbugs are almost exactly like sowbugs, but differ because they can curl up into balls and are thicker than sowbugs (PNNL). Isopods are related to a few water crustaceans including crabs, crayfish, and shrimp, so water is necessary for them to survive. For that reason, they live in damp or wet areas such as forests and meadows. Isopods have seven armour plates, called “pereonites,” that serve as protection from predators and have seven pairs of legs.
Experiment 1: Materials: • Alka-Seltzer tablets • Empty and clean water or soda bottles (12 oz to 24 oz) • Balloons • Water • Clock • Stove top Procedure: 1. Pour a sufficient amount of water (about 16 oz) into a small pot and place on the stove at high heat. 2. Watch the clock and after 30 seconds take the water off the heat.
The reaction to synthesize benzocaine was known as a Fisher esterification reaction. The Fisher esterification was reaction between alcohol and carboxylic acid in the presence of acid. The reaction was used to form an ester. In the experiment, sulfuric acid acted as a catalyst and necessary for this reaction to occur. There was a change between the –OH group of carboxylic acid to an –OCH2CH3 group in the reaction.
5. Join the side arm flask to source of vacuum. While dealing with this experiment you should always use thick walled tubing, the pressure will collapse with the Tygon tubing. 6. Wet the filter paper with a tiny amount of solvent to be used in the filtration.
Once dissolved, fill the rest of the volumetric flask up to the line on the neck of the flask. Again mix the solution. Use four, 10mL volumetric flask, and label them from 1-4. Add approximately 2mL of copper sulfate pentahydrate into flask 1, 4mL to flask 2,
This is added to the cream mixture and blended at high speed. Experiment 3: 7.5g is dissolved into a solution containing 5g of trisodium citrate. Heat is required to ensure full dissolution. 37.5 ml of cream is added and mixed at high speed in a blender at 55°c. 37.5 of sugar, 37.5 ml of ethanol are mixed together with 125 ml of water. This is added to the cream mixture and blended at high
The steps for the saponification soap making method can therefore be simplified into four: • Saponification: The fat and oil is mixed with the alkali and heated. The soap produced is the salt of a long chain carboxylic acid. • Glycerine removal: Saturated salt solution is added to dissolve the glycerine in the wet soap. A greater part of the glycerine is removed and separated from the soap whiles the other part remains to smoothen and soften the soap.
Again select the flask and select Distillation Head from the drop down menu. ➢ For the third time select the flask and choose Condenser from Distillation from the menu and for last time select the flask Distillation Take-off from the dropdown option. ➢ Select the 100 mL Graduated Cylinder from the Equipment option and put it underneath of distillation take-off.