2. Use the passage below and your knowledge to answer the questions that follow. Methane reacts with bromine to give bromomethane and hydrogen bromide. The mechanism for the reaction is called free-radical substitution and involves hemolytic fission of chemical bonds. The reaction proceeds via initiation‚ propagation and termination steps. (a) By what mechanism does bromine react with methane? (b) Write a balanced symbol equation for this reaction. (c) Bonds break in this reaction
Premium Alkene Hydrocarbon Methane
compound Functional group(s) Alkanes CH3CH3 ethane C – C and C–H Alkenes CH2 = CH2 ethene C=C Chemical tests/Observations Add liquid bromine in ultraviolet light (or sunlight): White fumes of HBr liberated; decolourisation of bromine occurs slowly (a) Add Br2 in CCl4 at room temperature: Decolourisation of bromine occurs immediately CH2 = CH2 + Br2 → CH2BrCH2Br (b) Add acidified KMnO4 at room temperature: Decolourisation of KMnO4 occurs immediately CH2 = CH2 + [O]
Premium Carboxylic acid Alcohol Sulfuric acid
bromination procedures. In order to create the alkyl halides‚ which are able to undergo chemical transformations more readily than the carbon-carbon double bond‚ onto the trans-stilbene the addition process of halogenation in needed. The typical reagents that are used‚ such as elemental bromine and liquid bromine‚ are dangerous and highly corrosive‚ so this experiment used an alternative method of bromination.
Premium Oxygen Hydrogen Chemistry
orientation. Diastereomers‚ which are stereoisomers that are not Enatiomers‚ they occur when two or more stereoisomers of a compound have different configurations at one or more‚ (but not all) of the stereocenters and are not mirror images. Stereochemistry ‚ may seem trivial at times due to the differences between stereoisomers being so subtle. However in nature‚ and more importantly‚ in a biological system such as the body‚ the subtle differences have wide sweeping implications. In living organisms
Premium Enzyme
result of the two reactions is the depletion of ozone and atomic oxygen.6 Chlorofluorocarbons (CFCs)‚ halons‚ and methyl bromide are a few of the ozone depletion substances (ODS) that break down ozone under intense ultraviolet light. The bromine and fluorine in these chemicals act as catalysts‚ reforming ozone (O3)
Premium Ozone depletion Ozone layer Chlorine
Note the appearance of the flame. 2) Shake 1cm3 (1 teat pipette full) of bromine water with 3 or 4 drops of cyclohexene in a test tube. Observe what happens. 3) Add 2 or 3 drops of potassium manganate (VII) solution to 2cm3 of bench sulphuric acid in a clean test tube. Add 3 or 4 drops of cyclohexene and shake. Observe what
Premium Alcohol Oxygen Water
DMF‚ CH3CN‚ HMPA Notes: The SN2 reaction is bimolecular - it depends on amounts of nucleophile and leaving group In synthesis‚ always convert an OH leaving group into an OTs leaving group Converting an OH into an OTs will NOT change the stereochemistry!! SN2 reaction goes with inversion about the stereogenic carbon SN1 Reaction Substrate: SN1 reactions work best on a TERTIARY! NO SN1 ON A PRIMARY!! Order of reactivity: 3 > 2 Benzylic and Allylic carbons have increased reactivity because
Premium
Observations were noted‚ such as changes in color and product formation. Iodine test‚ bromine test‚ Baeyer Test‚ Chloroform and aluminum chloride‚ fuming sulfuric acid‚ acetyl chloride‚ chromic acid‚ iodoform‚ Lucas’ test‚ Anilide formation‚ ester formation‚ hydrolysis‚ hydroxamic acid‚ Benedict’s test‚ Chromic test‚ 2‚4-Dinitrophenylhydrazine‚ Fehling’s solution‚ Schiff’s reagent‚ Tollen’s test‚ bromine water‚ cerric ammonium nitrate‚ ferric chloride‚ esterification‚ sodium bicarbonate‚ silver
Premium
Acetylene gas was used for the selective reactivity of hydrocarbons to functional group tests; Bayer’s test‚ Bromine test light‚ Bromine test dark‚ and Tollen’s test. In Bayer’s test‚ only Acetylene‚ Eugenol and Unknown hydrocarbon 2 reacted positively and the rest retain the purplish color of KMnO4. On the other hand‚ the five compounds in Bromine test with light reacted positively. In Bromine test dark‚ Hexane and Unknown hydrocarbon 1 did not react because light (UV) is absent. Lastly‚ in Tollen’s
Premium Hydrocarbon Alkene Functional group
The reaction of 0.139 grams of trans-cinnamic acid‚ 0.8 mL of glacial acetic acid‚ and 1.0 mL of 1.0 M of Bromine in acetic acid was recrystallized to form a solid‚ clear‚ crystal- like product. The melting was taken from the recrystallized product to determine what had been obtained. The melting point was found to be 130.5°C-133.7°C. Concluding that the product formed from the addition of bromine was a mixture of the erythro-2‚ 3-dibromo-3-phenylpropanoic acid‚ which has a known melting point of 204°C
Premium Water Solid Liquid