Citric Acid On The Viscoelasticity Of Cornstarch

Cornstarch was the next powder experiment on. Cornstarch is a white, soft powder generally used as a thickening agent in liquid-based foods such as soups or sauces. When mixed with lower temperature liquids, it forms a past/slurry. As the starch is heated, the molecular chains unravel, allowing them to collide with other starch chains to form a mesh, thickening the liquid (Starch gelatinization). When mixed with a fluid, cornstarch can make a non-Newtonian fluid, for example, adding water creates Oobleck while adding oil creates an Electro rheological fluid (a suspension of extremely fine non-conducting particles which can be up to 50 micrometers in diameter) (Cornstarch).

Sucrose has a molar mass of 342.3 g/mol. It has a melting point range of 185-187°C and can be an irritant.

The purpose of this experiment is to exemplify how differences in molecular weight allow separation of polymers from their monomers. Methods of dialysis and gel filtration chromatography will be used to separate a glucose monomer from a starch polymer. Colorimetric glucose oxidase assay will be used to monitor the presence of glucose and a colorimetric iodine assay will be used to monitor the presence of starch in prepared solutions after separation

In conclusion what makes Oobleck act like both a liquid and a solid? In your mind think that you can see the individual molecules of corn flour and water then think about how they might act when being pushed and pulled. The corn flour and water mixture will act like a solid and a liquid this type of mixture is an example of suspension. The particles stay undissolved in a liquid and corn flour molecules are dispersed into the water. If the cornstarch mixture is pinched, it causes the molecules to go closer together. The effect of the force traps the water between the flour molecules to form a solid shape. When you let go the pressure of your fingers the corn flour will be able to flow like liquid. Viscosity is the resistance for a liquid to

Also by using the molecular weight of glucose (342.3) it can be determined that the average degree of polymerization of the corn syrup solids is 2.669. These numbers were calculated based on boiling point data. A freezing point experiment was not conducted. This data makes sense, for corn syrup solids are created via hydrolysis of starch and consist of a mixture of glucose, maltose, and small glucose oligomers. The molecular weight/average degree of polymerization determined via this experiment directly correlates with that

• Thirdly, we tried to maintain the temperature by keeping the test tubes in a regulated room. If the temperature were to increase it would cause the kinetic energy of the sucrose solution increase and if the temperature were to decrease it would cause the kinetic energy of the sucrose solution to decrease.

The purpose of this experiment was to see if altering the ingredients of a bath bomb affected the effervescent when placed in water. When a bath bomb is submerged in water the ingredients caused it to fizz, releasing a scent and changing the color of the water. This bath bomb experiment requires two recipes, the first recipe which was labelled as “normal”, contained less cornstarch than the other recipe. In addition to the “normal” recipe, the other recipe was labelled “extra” because it contains more cornstarch. During this process, by adding or subtracting ingredients the eversences of the bath bomb changed. If more cornstarch is added to the recipe, the bath bomb will not fizz as much when placed in water. This is caused by the cornstarch,

This corn starch gets processed by the enzyme glucose isomerase so that a high majority of its glucose is transformed into fructose. Then corn syrup is produced.

In addition, the diethyl ether solution was decanted into the round bottom flask (50 mL). Afterwards, the washed Na2SO4 and the Erlenmeyer flask with additional diethyl ether (5 mL) was added to the round bottom flask, mentioned earlier. Later, the round bottom flask was placed in the rotary evaporator. In addition, the acetanilide flask and 3-chlorobenzoic acid was weighed and tared to determine the mass. Not to mention, the mass-% of 3-chlorobenzoic acid and acetanilide was calculated. Lastly, the melting points of acetanilide and 3-chlorobenzoic acid was

Jensen, W. B. (2008). The origin of the Polymerconcept. Journal of Chemical Education , 85 (5), 624-629. Kurt R. Mathews, J. D. (2004). Quantitative Assay for Starch by Colorimetry Using a Desktop Scanner.

1. 5 sucrose solutions were made of increasing molarity: 0.2 M, 0.4 M, 0.6 M, 0.8 M, 1.0M. 2. 50 mL of each unknown solution were poured into 5 separate cups. A slice of potato was placed into 5 equal cylinders. 3. The mass of the 5 potato cylinders were then recorded. 4. The cylinders were placed into the foam cups with solution and covered with plastic wrap. It is to be left overnight. 5. The room temperature was recorded in Celsius. 6. The cylinders are then to be removed from the cups and carefully blotted of any excess solution. 7. The mass of the potato cylinders were recorded afterwards.

An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water

The purpose of this lab was to study colligative properties. These properties are properties that are affected when a solute is added to a solvent. Thus, the amount is important, not the actual type of substance, for the colligative properties. A couple types of this property are the freezing point and boiling point of a substance. (1)

The objectives of this lab are, as follows; to understand what occurs at the molecular level when a substance melts; to understand the primary purpose of melting point data; to demonstrate the technique for obtaining the melting point of an organic substance; and to explain the effect of impurities on the melting point of a substance. Through the experimentation of three substances, tetracosane, 1-tetradecanol and a mixture of the two, observations can be made in reference to melting point concerning polarity, molecular weight and purity of the substance. When comparing the two substances, it is evident that heavy molecule weight of tetracosane allowed

The viscosity of different formulation at 10% water as follows, F1 (28±6.08 Cp), F2 (257±12.12 Cp), F3 (181±23.26 Cp) and F4 (141±29.82). This might be to the semisolid characteristics of Cremophor RH while T80 is liquid at room temperature [36]. It was stated that the introduction of Cremophor RH surfactant into the interface film increases progressively a number of ethylene oxide units available for bonding with the surrounding water molecules, providing a much higher extent of hydration as well as droplet interactions compared to T20 [9].