This essay sample on Halohydrogenation provides all necessary basic info on this matter, including the most common “for and against” arguments. Below are the introduction, body and conclusion parts of this essay.
Therefore, alkyl halides are compounds that have a halogen atom bonded o a saturated, SSP hybridism carbon atom. These could be classified according to the number of alkyl groups attached to the carbon that is bonded to the halogen atom. A methyl halide does not contain any alkyl group, a primary halide has one alkyl group, a secondary halide has two alkyl groups, and a tertiary halide has three.
Synthesis of alkyl halides can be performed from a variety of starting materials and specific mechanisms: from alleles by addition, from alkaline by substitution, and from alcohols via necrophilia substitution.
The reaction of alcohols with hydrogen halides, like HCI, Hub, and HI, would result to heir corresponding alkyl halides and water. The formation of alkyl halides has different mechanisms, depending on the alcohol used for the synthesis.
Tertiary alcohols react with hydrogen halides faster compared to the secondary and primary alcohols. Tertiary alcohols could react with hydrogen halides rapidly at room temperature, while the reaction of primary alcohols with hydrogen halides takes a longer time and should be at a high temperature.
Tertiary alcohols can be converted to their corresponding alkyl chlorides by the addition of concentrated hydrochloric acid to the alcohol. In this experiment, concentrated HCI is added to term-butyl alcohol to produce term-butyl chloride via SIN reaction. RICOH > RICOH > ARCHER > COACH Tertiary alcohols react readily with HEX alone to form alkyl halide, while secondary and primary require catalyst in the halo hydrogenation reaction.
Alkyl halide can be prepared from alcohol by reacting them with a hydrogen halide, HEX (X=CLC,BRB, or l).
The mechanism of acid catcalled substitution of alcohols are termed SIN and SON, where “S” stands for substitution while sub-“N” stands for necrophilia, and the number “1” and “2” is described as first order and second order especially. The “1” or “2” is also represent the reaction is monomolecular or bimolecular reaction. The secondary alcohols are more favor to react with hydrogen halides by both SIN and SON mechanisms. For primary or methyl alcohol, both molecules undergo SIN mechanism while tertiary alcohol undergoes SON mechanism.
In the reaction of a tertiary alcohol and a hydrogen halide, the initial steps are the propagation of the alcohol oxygen and then the formation of the carbonation. The hydrogen ion of the hydrogen halide would first bond with the hydroxide ion, OH-, of the alcohol forming water. The water armed could easily leave the alcohol, and this would result to the formation of a carbonation. The halide ion would then react with the carbonation, forming the alkyl halide. Based on the reactivity of hydrogen halides towards alcohols, HCI could readily react with tertiary alcohols.
In this experiment, the reaction of term- butyl alcohol with concentrated HCI at room temperature is analyzed. Ill. Methodology A. Synthesis of Term-Butyl Chloride The major reactants needed in this experiment are the term-butyl alcohol and the concentrated hydrochloric acid, HCI. First, ml ten-butyl alcohol and ml incinerated HCI were placed in a 125-ml separators funnel. The mixture was swirled gently without shaking, and was relieved of internal pressure by slowly opening the stopcock. The separators funnel was then placed on the ring stand allowing the two layers to separate.
The lower aqueous layer was drained and placed into a ml Erlenmeyer flask. Then, ml of saturated sodium bicarbonate solution was added into the organic layer remaining in the funnel. The previous steps was repeated. The organic layer was then transferred into a dry ml flask with a small amount of anhydrous calcium chloride. The liquid was decanted into a previewed ml beaker and the crude product was weighed. B. Qualitative Chemical tests for Reactivity Four small test tubes was labeled properly. Into two test tubes, 2-5 drops of the synthesized term-butyl chloride was added.
Into the two another test tubes, 2-5 drops of schoolchildren was added. To one test tube of each compound, 1 ml of potassium iodide solution was added and in the other two test tubes ml of silver nitrate solution was added. The stopper was placed in the test tube and the content was shaded vigorously. The time it takes to form any precipitation as noted. The differences in the results was also noted. IV. Data and Discussion Data 1. 1. A. Synthesis of Term-Butyl Chloride Hydrochloric acid t-butane t-butyl chloride Molecular Formula Condensed Formula Molecular Weight 17. G 3. 904 g HCI CHICHI Chocoholic (CHI)COCO (CHI)CLC 36. 458 g/mol 74. 12 g/mol 92. 562 g/mol 0. 64 g Volume % yield 15 ml 5 ml 13. 23 % Data 1. 1. B. Sample Computation 1. Weight of the vial container 13. Egg Weight of the crude product + vial = 14. Egg Weight of the crude product 2. Theoretical Yield -4. Egg Actual Yield = 0. Egg Percentage Yield = 13. 23% 3. Percentage Error 86. 78% gall get-butane gall = (Density HCI)(volume HCI) get-butane = (Density t- butane)(volume t-butane) – 1. 18 HCI * ml – (0. 7809 = 17. 7 g = 3. 904 g # of mol of (CHI)COCO = 3. Egg / 74. 12 g. Mol = 0. 0526 mol + HCI(as) + H2O(l) 1 mol of (CHI)COCO produces 1 mol of (CHI)CLC 0. 00523 mol of (CHI)COCO produces 0. 0523 mol of Theoretical WTG. Of (CHI)CLC = 0. 0526 mol * 92. 562 g. Mol-l 4. 8687 g Percentage Yield = Experimental Value X 100 Theoretical Value = 0. 64 g x 100 = 13. 14% Percentage Error = theoretical value – experimental value X 100 Theoretical value = 14. 8391 g -0. G X 100 14. Egg Qualitative Chemical tests for Reactivity Reagent I Time (seconds) I No PPTP. Formed, clear solution I Benzene chloride + Anal I White PPTP. Armed I Benzene chloride + Again 1 Reactivity I t-butyl chloride + Anal I Bubbles formed I t-butyl chloride + Again Right after Again was added = 0. 8 s I No PPTP. Formed I In this experiment, ml of term-butyl alcohol was reacted to Hydrogen chloride (HCI). By necrophilia substitution, the chloride was substituted to the alcohol to obtain the reaction below: Figure 1 It should be noted that excess amount of HCI was added to keep the reaction room going too fast and to avoid the formation of side reactions such as superimpose.
In addition, concentrated WHQL was used because concentrated WHQL is very volatile, thus, it prevents the possible escape of HCI vapor during its reaction with term-butyl alcohol. The reaction yielded the product term-butyl chloride. Data 1. 1 shows the details of this reaction. In the diagram above, the t-butyl alcohol acts as a nucleoli which attacks the proton from the hydration ion in the solution. According to Breasted Lowry Theory, the t-butyl alcohol is considered as a base in this reaction. This is cause it accepts a proton from the hydration ion and hence t-buttonholing ion is formed.
In order to become a stable molecule, the bond between the carbon and oxygen of the t-buttonholing ion breaks hydroelectrically. The breaking of bond between carbon and oxygen leads to the formation of a carbonation and a leaving group of water. Diagram 5 As shown in the diagram 5, the carbonation is formed and it is acts as lithosphere which is the species lack of electron. Due to the lacking of electron, another nucleoli, chloride ion, CLC-, tends to attack the carbonation and hence to achieve a stable molecule. The carbonation acts as a Lewis acid which accepts electron from the chloride ion, CLC- to form t-butyl chloride.
The formation oft-butyl chloride is synthesized via SIN mechanism is shown. The addition of concentrated hydrochloric acid into the t- butyl chloride causes the formation of cloudy solution is formed when stirring. The reaction between t-butyl alcohol and hydrogen chloride is a simple reaction which can take place in the room temperature. Two layers are formed after transferring the mixture into a separators funnel. Aqueous sodium bicarbonate solution is added into the organic to neutralize he acidic medium that caused by concentrated hydrochloric acid added.
Since sodium bicarbonate is an alkaline solution. The naturalization process between sodium carbonate and hydrochloric acid could be shown in the following chemical equation. Enhance (as) + HCI (as CO (g)) –> Niacin (as) + H2O (l) + CO (g) The sodium chloride salt, water, and gaseous carbon dioxide are formed in the naturalization process. The two layers are formed second time due to the formation of water in the naturalization. The sodium bicarbonate is highly soluble in aqueous layer which is being discarded together with aqueous rye. Cal (s) + H2O (I) ћ> Cal. H2O (s) Anhydrous Hydrated calcium chloride drying agent The presence of tertiary alkyl halides can be tested by using silver nitrate test. Some of the product formed in the experiment is added with silver nitrate solution. The observation we obtained is a white precipitate is formed after addition of silver nitrate solution. This is because the t-butyl chloride containing tertiary alkyl group which reacts rapidly via SIN mechanism with the silver nitrate to form a precipitate of silver chloride. As shown in the diagram above, a highly polar solvent ethanol) is used to dissolve the butyl chloride.
The chloride will unionize to the butyl caution and chloride ion. The butyl caution will react with the alcohol solvent to form the butyl ethyl ether via formation of C-O bond. The HCI is formed in this reaction too. In this case both products are soluble; however, if silver ion is present in the solution, insoluble Gall will form and a precipitate will be visible. Primary halides do not react in this test, and secondary reacts only slowly with heating. V. Questions 1 . Write the complete step-wise mechanism for the reaction f tubful alcohol with concentrated hydrochloric acid. 2.
What is the purpose of sodium bicarbonate solution ? Dehydrate calcium chloride? Sodium bicarbonate was added to act as neutralize of the acid in the medium. Dehydrate calcium chloride was added to remove the water droplets. It acts as a solidifying agent. 3. What is the limiting reagent ? The limiting reagent is ten-butyl alcohol. 4. Give two observations for this experiment. On the addition of Again solution, the term-butyl chloride resulted as white solution with white precipitate occurred directly after adding Again. While schoolchildren it has a clear solution with bubbles at the bottom.
On the other hand, addition of potassium iodide solution on term-butyl chloride was observed as colorless and no precipitate form while in the schoolchildren, a colorless s solution with a bubble formation at the bottom was observed. 5. Explain the results of the calculated percentage yield and percentage error. It can be seen in Data 1. B that an actual yield of 0. 64 g of term-butyl chloride was obtained; and compared to the theoretical yield of 4. 8391 g, the actual yield was considerably distant. From this data, the actual percent yield is 13. %; in addition, it can be identified that a deviation of the actual yield from the theoretical gave 86. 78% error, which suggests a substantial product yield less than the expected product yield. VI. Conclusion. In this experiment, the synthesis of an alkyl halide from an alcohol was carried out, using HCI as the hydrogen halide. Through necrophilia substitution, the reaction between term-butyl alcohol and HCI gave off term-butyl chloride and water. From the synthesis process done, 0. 64 g of term-butyl chloride was obtained, suggesting an actual percent yield of 13. 23%.