This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone.
The aim of this experiment was to prepare a buffer for an unknown amino acid with the goal of identifying the unknown amino acid. The objective was to use the Henderson Hasselbalch equation to determine the buffer capacity, and to use the pKa values and molecular weight, to identify the unknown amino acid through acid-base titrations. Titration was done on the unknown amino acid with a strong acid and base while titration was done on NaCl, which acted as a blank for identifying the unknown amino acid and was used to find the true titration curve of the amino acid. The pka values were found to be 1.95 and 8.88, and the molecular weight 133.98 g/mol. Moles extrapolated from the titration curve were used to find the molecular weight of the unknown amino acid, along with the pkas and the pI.
The effect of pH on the speed of enzyme interaction with substrate chemicals Hypothesis: About pH: If the pH level is less than 5, then the speed of the enzyme reaction will be slower. About temperature: If the temperature stays the same, then the speed of the enzyme reaction will not be completely affected. Background information: The function of enzymes is to speed up the biochemical reaction by lowering the activation energy, they do this by colliding with the substrate. All enzymes are under the class of protein biomolecule. Amino acids are the basic units that are combined to make up an enzyme.
Water acts as a leaving group in the third step and is removed from the reaction intermediate. In the fourth step, the molecule undergoes deprotonation with the help of the concentrated sulfuric acid to form isopentyl acetate. The reaction that was carried out in the experiment was a reversible reaction. In order to obtain as much isopentyl acetate as possible, Le Chatelier’s principle was used to ensure that we were able to collect a sufficient amount of isopentyl acetate. Le Chatelier’s principle says that if you disturb a system in equilibrium the equilibrium will shift in order to account for the disturbance.
The iodine test determines the presence of starch in biological materials. It is predicted that, if starch is not present, the solution with iodine remains yellow. However, if starch is present the solution with iodine becomes a blue-black colour. Plants have starch as the storage polysaccharide (glucose units held together by glycosidic bonds) while animals have the equivalent of glycogen. In this experiment, the dark blue colour is visible because of the helical amylose and amylopectin reacting with iodine (Travers et al., 2002).
Abstract In this experiment, the reaction kinetics of the hydrolysis of t-butyl chloride, (CH3)3CCl, was studied. The experiment was to determine the rate constant of the reaction, as well as the effects of solvent composition on the rate of reaction. A 50/50 V/V isopropanol/water solvent mixture was prepared and 1cm3 of (CH3)3CCl was added. At specific instances, aliquots of the reaction mixture were withdrawn and quenched with acetone. In addition, phenolphthalein was added as an indicator.
The principal product in this case is R-Nuc. In such reactions, the nucleophile is usually electrically neutral or negatively charged, whereas the substrate is typically neutral or positively charged. An example of Nucleophilic substitution is the hydrolysis of an alkyl bromide, R-Br, under basic conditions, where the attacking nucleophile is the base OH− and the leaving group is Br−. R-Br + OH− → R-OH + Br− Nucleophilic substitution reactions are commonplace in organic chemistry, and they can be broadly categorized as taking place at a carbon of a saturated aliphatic compound carbon or (less often) at an aromatic or other
This creates a cube-shape and makes what we know as table salt. The bond that forms water molecules is called a hydrogen bond. It takes the positively charged hydrogen from water and bonds it with the negative charge of the oxygen in another water molecule. This may create a weaker bond than a covalent bond but it is strong enough to affect the atoms involved. Hydrogen bonds help determine the three dimensional shape of the molecules.
This agar comprise of dextrose, lactose and sucrose, which acts as the carbohydrates sources. The medium osmotic balance is maintain by Sodium chloride The fermentation of the carbohydrate lead to acid production of yellow colour agar, detected by the pH indicator in the media, phenol red. Detection of hydrogen sulfide is through the indicator Ferric Ammonium citrate. A black colour will be seen in the medium from the hydrogen sulfide production from thiosuplhate due to FeS production. ,
During the experiment, a colourless solution of potassium iodide and a solution of sodium persulfate, starch and thiosulfate will be combined into a beaker to later react into a blue-black complex. The elapsed time from when colourless solutions are combined to the colour change is dependent on the reactant concentrations of sodium persulfate and potassium iodide. Experiments will be conducted by systematically varying the concentrations of persulfate and iodine. The times recorded will be utilised to determine the rate of reaction and