Org Worksheet Reaction Mechanisms

SL practice 1 Reactivity 3.2.9—Functional groups in organic compounds may undergo oxidation. Write the reactions for the following including all conditions and/or catalysts. Write NR if no reaction would occur. a) oxidation of 2-methyl-1-propanol b) oxidation of 3-methyl-3-pentanol c) oxidation of propanol Reactivity 3.2.10—Functional groups in organic compounds may undergo reduction. Write the reaction for the reduction of a)​ methanoic acid to methanol. b)​ 2,3-dimethylbutanoic acid c)​ What does the catalyst provide? The catalyst is LiAlH4 Write the following in order of degree of oxidation. Show oxidation numbers CH3OH,,CO2, HCHO, CH4, HCOOH Reactivity 3.2.11—Reduction of unsaturated compounds by the addition of hydrogen lowers the degree of unsaturation. ➢​ Deduce the products of the reactions of hydrogen with alkenes and alkynes. ➢​ Reactivity 3.4—Why are some reactions of alkenes classified as reduction reactions while others are classified as electrophilic addition reactions? Write the reaction for: a)​ Hydrogenation of cyclohexene b)​ Hydrogenation of 1-octene c)​ Compare the oxidation number of the Carbons on ethene after hydrogenation and after electrophilic addition of hydrogen bromide. SL practice 2 Reactivity 3.3.2—Radicals are produced by homolytic fission, e.g. of halogens, in the presence of ultraviolet (UV) light or heat. a)​ Show the homolytic fission of Cl2 b)​ What is this step called in Free Radical Substitution? Reactivity 3.3.3—Radicals take part in substitution reactions with alkanes, producing a mixture of products. a)​ Write the reaction mechanism for the halogenation of ethane with bromine. Reactivity 3.4.1—A nucleophile is a reactant that forms a bond to its reaction partner (the electrophile) by donating both bonding electrons. Recognize nucleophiles in chemical reactions. a)​ Which of the following are nucleophiles? How do you know? (1) NH₃ (2) H₂O(3) BF₃ (4) OH⁻ Reactivity 3.4.2—In a nucleophilic substitution reaction, a nucleophile donates an electron pair to form a new bond, as another bond breaks producing a leaving group. Write the reaction for the nucleophilic substitution of the following symmetrical compounds. Be sure to show arrows to indicate movement of electrons. a)​ Ethylbromide (1-bromoethane) + sodium hydroxide → b)​ chloroethane + cyanidel → Reactivity 3.4.3—Heterolytic fission is the breakage of a covalent bond when both bonding electrons remain with one of the two fragments formed. Explain, with equations, the formation of ions by heterolytic fission. a)​ Show the heterolytic fission of chloromethane SL practice 3 Reactivity 3.4.4—An electrophile is a reactant that forms a bond to its reaction partner (the nucleophile) by accepting both bonding electrons from that reaction partner. Which of the following are electrophiles? Reactivity 3.4.5—Alkenes are susceptible to electrophilic attack because of the high electron density of the carbon–carbon double bond. These reactions lead to electrophilic addition. (SL does not need to know mechanisms) a)​ 2-butene + HBr → b)​ Ethene + I2 → c)​ 3-pentene + H2O Reactivity 3.2.4—Acids react with reactive metals to release hydrogen. a)​ Zn + HCl → b)​ Magnesium + sulfuric acid → Reactivity 1.3.1—Reactive metals, non-metals and organic compounds undergo combustion reactions when heated in oxygen. Deduce equations for reactions of combustion, including hydrocarbons and alcohols. a)​ b)​ c)​ d)​ Sodium + oxygen → Ethanol + oxygen → Benzene + oxygen → Sulfur + oxygen→ Reactivity 1.3.2—Incomplete combustion of organic compounds, especially hydrocarbons, leads to the production of carbon monoxide and carbon. Deduce equations for the incomplete combustion of hydrocarbons and alcohols. a)​ Write the equation for the incomplete combustion of butanol b)​ Write the equation for the incomplete combustion of heptane SL practice 4 Reactivity 2.1.1—Chemical equations show the ratio of reactants and products in a reaction. Deduce chemical equations when reactants and products are specified. Include state symbols. a)​ Solid carbon reacts with oxygen gas to produce carbon dioxide b)​ Copper metal reacts with aqueous silver nitrate to make copper (II) nitrate and silver. c)​ Iron (III) hydroxide decomposes to produce iron (II) oxide and water. Structure 2.4.5—Addition polymers form by the breaking of a double bond in each monomer. Represent the repeating unit of an addition polymer from given monomer structures. a)​ Which of these is a monomer for an addition polymer? b)​ Draw a section of the polymer containing three repeating units that could be made from the following monomer c)​ What monomer was used to make this addition polymer SL practice 5