Hydrocarbons
Define hydrocarbons and provide one example.
Explain why alkanes are also referred to as paraffins.
List and briefly describe the three main categories of hydrocarbons based on the types of carbon-carbon bonds they contain.
Examine the Friedel-Crafts alkylation of toluene (\text{C}_6\text{H}_5\text{CH}_3) with chloromethane (\text{CH}_3\text{Cl}) in the presence of anhydrous \text{AlCl}_3. Predict the major organic products formed.
Identify a catalyst commonly used for the hydrogenation of alkenes.
What is the general formula for the homologous series of alkanes?
List three distinct methods used for the preparation of alkanes and name the starting material for each.
Justify why alkynes containing a terminal triple bond are acidic in nature, whereas non-terminal alkynes, alkenes, and alkanes are not.
Calculate the total number of sigma (\sigma) and pi (\pi) bonds present in the structure of 3-Methylbut-1-ene.
Critique the original Kekulé structure of benzene. Propose two key experimental observations that it failed to explain.
Critique the statement: "Wurtz reaction is a suitable method for preparing propane." Justify your critique by formulating the expected reaction products when a mixture of chloromethane and chloroethane is treated with sodium in dry ether.
Name the process by which n-alkanes having six or more carbon atoms are converted into benzene or its homologues upon heating.
Design a chemical test to distinguish between but-1-yne and but-2-yne. Propose the reagents you would use and formulate the chemical equations for the reactions.
Describe the two extreme conformations of an ethane molecule. You can represent them using Newman projections.
Define the term 'decarboxylation' and write the chemical equation for the decarboxylation of sodium ethanoate.
A hydrocarbon 'Y' has a molar mass of 70 g/mol. On catalytic hydrogenation, it consumes one mole of to give 2-methylbutane. Propose all possible structures for 'Y' and provide their IUPAC names.
Explain why benzene is unusually stable, even though its structure contains three double bonds. Your explanation should include the concepts of resonance and orbital delocalization.
An aromatic hydrocarbon 'A' () on vigorous oxidation with acidic gives a dicarboxylic acid 'B' (). 'A' can exist in three isomeric forms. Propose the structures for the three isomers of 'A' and formulate the oxidation reaction for each isomer to show how the respective product 'B' is formed.
Draw the structural formulas for all the chain isomers of hexane (\text{C}6\text{H}{14}) and write their corresponding IUPAC names.
Provide the structure of the vicinal dihalide that would yield propyne upon treatment with alcoholic \text{KOH} followed by sodamide (\text{NaNH}_2).
Analyze the structure of but-2-ene. Demonstrate with diagrams why it exhibits geometrical isomerism and name the two isomers.
Design a multi-step synthesis pathway to convert calcium carbide () into acetophenone (). Justify each step with the appropriate reagents, conditions, and chemical equations.
Propose a reason why Friedel-Crafts alkylation of benzene with 1-chloropropane gives isopropylbenzene as the major product instead of n-propylbenzene.
An unknown alkene 'X' with the molecular formula undergoes reductive ozonolysis (, then ) to produce only one product, propanone (). Propose a structure for alkene 'X' and justify your reasoning.
State Hückel's rule for determining aromaticity.
Explain Markovnikov's rule for the addition of hydrogen halides to unsymmetrical alkenes. Provide a suitable example.
Explain the formation and structure of a carbon-carbon double bond in alkenes, detailing the roles of sigma () and pi () bonds and the state of hybridization of the carbon atoms.
Identify the sodium salt of the carboxylic acid that would be required to prepare 2-methylpropane using the soda-lime decarboxylation reaction.
Justify why trans-but-2-ene has a higher melting point but a lower boiling point than its cis-isomer.
Examine the following condensed structural formula and write its correct IUPAC name: (\text{CH}_3)_2\text{CH}-\text{CH}_2-\text{C}(\text{C}_2\text{H}_5)_2-\text{CH}_3.
Propose an explanation for why the peroxide effect (anti-Markovnikov addition) is observed with HBr but not with HCl or HI.
Evaluate the aromaticity of the cyclopentadienyl anion and the cycloheptatrienyl cation using Hückel's rule. Justify your conclusion for each species.
Summarize the concept of the directive influence of a functional group in a monosubstituted benzene. Explain the difference between ortho/para-directing groups and meta-directing groups, and provide one example for each.
Formulate a reaction sequence to convert benzene into m-nitrobenzoic acid. Justify the chosen order of reactions based on the directive influence of the functional groups.
Describe the following reactions, providing one chemical equation as an example for each: (a) Wurtz reaction (b) Friedel-Crafts alkylation (c) Ozonolysis of an alkene (d) Kolbe's electrolytic method (e) Pyrolysis
Formulate a complete mechanism for the free-radical chlorination of propane in the presence of UV light. Predict all possible monochlorinated products and evaluate their relative yields, justifying your prediction based on the stability of the intermediate free radicals.
Design a laboratory preparation for ethene gas from ethanol. Create a labeled diagram of the apparatus, propose the necessary reagents and conditions, and formulate the chemical equation and mechanism for the reaction.