Since alkenes are immiscible with concentrated HBr, tetrabutylammonium bromide is used as a phase-transfer catalyst. It forms a complex with HBr and extracts it from the aqueous phase into the organic phase where the alkene is. This dehydrates the acid, making it more reactive so that the addition reaction is possible. Rapid stirring is required in order to maximize the surface area
Step four is basically just where water can now enter and bind to the active site through hydrogen bonding, which is between the hydrogen atoms of water and the Histidine-57 nitrogen. The fifth step is the step where the water and oxygen make a nucleophilic attack on the carbonyl carbon of the acyl-enzyme intermediate. This pushes the carbonyl’s electrons onto the carbonyl carbon, while the Histidine-57 takes one proton from the
The selective agents in the agar such as Sodium Thiosulfate and Ferric Ammonium Citrate support visualization of hydrogen sulfide production under alkaline conditions. The release of hydrogen sulfide is from the fermentation of xylose by Salmonella hence resulting in red colonies with black centres. Black centre in the colony is resulted from the reaction with iron salts (III). Non-Hydrogen sulfide Salmonella will produce only red colony. ,
The oxidation products are known to be health hazards and are linked to aging, cancer and heart disease. The double bonds of -3 fatty acids are highly prone to oxidation due to their large number and position in the fatty acid chains. Initiators such as light, heat, oxygen and transitional metals produce lipid radicals and lipid peroxides leading to formation of conjugated dienes and trienes through cis-trans isomerization processes and shifts in the double bonds.  The unstable lipid peroxides further degrade to form more harmful secondary oxidation products such as carboxylic acids, ketones and aldehydes (e.g. cis-4-heptenal, (Z,Z)-3,6-nonadienal, (E,Z)-2,6-nonadienal) which cause the undesirable odor and taste associated with rancid oil.
The reaction the occurred in the experiment was a reaction between acetic acid and isopentyl alcohol to form isopentyl acetate and water. The esterification of acetic acid with isopentyl alcohol occurs in four steps. The first step in the reaction mechanism is the protonation of acetic acid with a proton from the concentrated sulfuric acid that was added to the reaction mixture. In the second step, acetic acid reacts with the isopentyl alcohol to form a reaction intermediate which undergoes proton transfer or rearrangement protonation. Water acts as a leaving group in the third step and is removed from the reaction intermediate.
An EAS reaction pertains to the substitution of an aromatic hydrogen for an electrophile by means of an electrophilic attack on the aromatic ring which in this case is benzene. The product of the reaction was purified by recrystallization and characterized by both NMR spectra and melting point
CML103 - Term paper Methanol Synthesis Industrial process/chemical synthesized: Today in industries, generally the basis for the manufacture of methanol is synthesis gas (normally called as syn gas). Syn gas is a mixture of carbon-monoxideand hydrogen. By syn gas :- For the production of methanol to be independent of feedstock material, the three steps that can be followed are :- Syn gas preparation, Methanol synthesis and, Methanol purification that contain the reactions given below a.) CO (g) + 2H2 (g) CH3OH (g) H25oC = -90.79 KJ/mol b.) CO2 (g) + 3H2 (g) CH3OH(g) + H2O (g) H25oC = -11.90 KJ/mol c.) CO2 (g) + H2 (g) CO (g) + H2O (g) H25oC = 41.01 KJ/mol The above three given chemical reactions are reversible reactions that is why we must have to control the temp., pressure and syngas mixture for the production of intermediate or products.
First of all one reason that there should be warning labels on sugary drinks is because sugary drinks are very unhealthy to be consuming a lot of and could have several different diseases such as diabetes, heart attacks, obesity, liver damage, ext. "Obesity is the most common to occur from abusing sugary beverages." ( Lloyd, 2014) Since sugary drinks can be deadly and cause diseases plus are very unhealthy it would be a good idea to put warning labels on the containers to let the consumers know these things, to let the people know that abusing added sugar they could become obese, unhealthy, and/or have organ problems such heart attacks or large amounts of sugar cause liver fat. Obesity can be caused because added sugar is highly fattening. Sugary beverages are also the easiest way to consume excessive amounts of fructose says Joe Leech in his article " 13 ways that sugary soda is bad for your health" Sugar is added to so many of the foods we eat
(2010), different structure of crystal will have different physical characteristics, thus can alter the use of the chemical. The physical characteristics that may be differ include solubility, density, melting point, colour, size and shape of the crystal. In term of stability, β’ is more stable than α but less stable than β. β’ crystal form is suitable for margarine, shortening and bakery products because it gives smooth texture, shiny surface and good meltdown properties. Meanwhile, β will gives hard texture, loss of spreadibility, brittle and unpleasant product. To test the polymorphism of the fat, X-ray diffraction technique can be used.
They belong to the so-called “dirty dozen” - a group of dangerous chemicals known as persistent organic pollutants (POPs). Dioxins are of concern because of their highly toxic potential. Experiments have shown they affect a number of organs and systems. Once dioxins enter the body, they last a long time because of their chemical stability and their ability to be absorbed by fat tissue, where they are then stored in the body. Their half-life in the body is estimated to be 7 to 11 years.