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
The graphical illustration of the representative configurations under consideration is depicted in Figure 2. Possible interactions which considered for HOY molecules with HC3OX are including hydrogen bonding (O···H) and halogen bonding (X···Y,O···X) which have been denoted as XYm. The X is representing the cyclopropenone (HC3OF, HC3OCl, HC3OBr, and HC3OI were defined as F, Cl, Br and I, respectively); Y shows the HOY molecules (HOF, HOCl, HOBr, and HOI were defined as F, Cl, Br and I, respectively) and m was applied for displaying the type of complex that formed between them. For example FI1 shows type 1 complex of HC3OF with HOI or BrBr2 is illustrating type 2 complex of HC3OBr with HOBr. The XY1 type shows O···H interactions, which HOY acts as hydrogen bond donor (HBD).
In organic and inorganic chemistry, nucleophilic substitution reactions are the most well studied and useful class of reactions. These reactions can occur by a range of mechanisms, the two studied in this lab are the SN1 and SN2 reactions. In a nucleophilic substitution, the nucleophile is a electron rich chemical species which attacks the positive charge of an atom to replace a leaving group. Since nucleophiles donate electrons, they are defined as Lewis bases. The positive or partially positive atom is referred to as an electrophile.
Concentration of acid and reaction time Aim In this experiment, I’m going to find out the relationship between concentration (mole) of acid and carbonate’s reaction. Hypothesis If the concentration of acid is stronger, then the film canister will pop (react) faster. Because the concentration of Sodium carbonate is always same in my experiment, so the factor that changes the volume of carbon dioxide is concentration of Hydrochloric acid. If the concentration gets bigger, the proportion of acid gets bigger, which means there are more particles (molecule) that will bond with other particles (molecule). For this experiment, the proportion to get a CO2 is 2HCl+Na2CO3 = CO2.., which is 2+ Na2CO3 : 1.
Crystallization is attained by a three step process, first supersaturation state, second nucleation and third growth of crystals. For solute to leave the solution a certain degree of supersaturation is necessary, where the solvent will contain excess of solute that it can contain at a particular temperature , . Some of the methods that induce supersaturation are methods based on change in temperature, solvent removal, drowning out and reaction partners . Crystallization of APIs has been studied using various methods though cooling crystallization  and anti-solvent crystallization  have been most common. Even though cooling crystallization and anti-solvent crystallization are convenient, it has major drawbacks in terms of slow rate of crystallization, high supersaturation degree , solvent and anti-solvent selection based on solubility.
Properties of Ionic and Covalent Substances Lab Report Introduction The purpose of this lab was to determine which of the following substances: wax, sugar, and salt, are an ionic compound and which are a covalent compound. In order to accurately digest the experiments results, definitions of each relating factor were researched, leading to the following information: ionic compounds are positive and negatively charged ions that experience attraction to each other and pull together in a cluster of ionic bonds; they are the strongest compound, are separated in high temperatures, and can be separated by polar water molecules. A covalent compound is formed when two or more nonmetal atoms share valence electrons; covalent compounds are also categorized into two sections: polar covalent and nonpolar covalent. Furthermore, polar covalent compounds dissolve in water, while nonpolar covalent compounds do not. Dissolving is the process in which a solvent and a solute interact with each other and form a solution.
Experimental data determined that there was a difference of .003g between using the single solvent in comparison to the paired solvent. Data suggests that Water is the best solvent that will allow for better saturation and the best recrystallization of benzoic acid, this is largely due to water being a polar molecule whose properties allow for carboxylic acid groups, such as the one found in benzoic acid, to disassociate and donate protons to the water
This causes the indicator to change colour due to the colour difference from the undissociate molecules. Strong acids and strong bases are strong electrolytes and are assumed to ionize completely in the presence of water. Weak acids however, only ionize to a limited extend in water. Any weak or strong acids when in contact with any weak or strong alkali will start to undergo neutralization regardless of their volume. When an indicator which is present in the acid-base mixture and have experienced colour change, it indicates that the mixture is in right proportions to neutralize each other and is also known as the equivalence point.
Some bidentate directing groups also used for these heterocyclic syntheses. Chatani et al discovered a nickel catalyzed synthesis of isoquinolones from aromatic amides containing 2-pyridylmethylamine moiety 1.72 by oxidative cycloaddition with alkynes (Scheme 1.23).32 The reaction proceeds via coordination of amide 1.72 to the nicker center in a N,N-fashion and forms a cyclometallated complex. Insertion of alkyne into this ortho-metalated complex, followed by reductive elimination afforded the
Cross Condensation of aldol 2015007632 Dowrie, K Contents Reaction 1 Introduction 1 Experiment Procedure 2 Experimental results 3 Table of calculations 3 Calculations 3 NMR 4 TLC 4 References 5 Reaction Introduction An aldehyde reaction is when aldehydes and keytones, both containing an α-hydrogen in the presence of an alkali group condenses and forms an enone. Acetone has α-hydrogens on each side. The proton can be removed and therefore giving a nucleophile anion. The aldehyde carbonyl is more reactive than the keytone and so it reacts rapidly with the anion. This product undergoes base catalysed hydration giving dibenzalacetone.
But, in the case of speed of tarnishing between the two elements, potassium was faster than sodium. It dissolves completely in water quicker than sodium. Alkali metals tend to react violently or explosively with the water; however its reaction with methanol is gentler. The reaction of sodium or potassium with methanol caused a fizzing (gas released) until the metal
Hydrogen chloride has a very powerful smell. It is in the form of a gas but only when it is at room temperature which is approximately 25 Celsius and when the pressure is high. When you add water to hydrogen chloride then it breaks down into small pieces which are known as dissolving. The solubility of hydrogen chloride is very high this means that it can dissolve in water quickly because it dissolves many times in its own solution (the gas form of hydrogen chloride). It is very soluble because the smaller the chain of the molecules are then the energy will be required in small quantities however if the chain is long then it will need more energy so that means that the longer chain will have a slow reaction.
The goal of this experiment was to synthesize the unknown ester through Fischer Esterification. This procedure involves treating a carboxylic acid with an alcohol and a strong acid catalyst. This procedure was also catalyzed with heat at 160oC-180oC, to keep the temperature from exceeding the boiling points of the compounds in use. The acid catalyst protonated the double bonded oxygen atom to force the atom to pull two electrons away from the double bond in order to stabilize the atom’s charge. As this electron shift occurred, the alcohol attacked the carbocation that lost its double bond.