Topic 18 Flashcards
How many moles of oxygen is required to combust 1 mole of benzene, explain why the combustion of benzene has a highly smoky flame.
7.5 moles of O2. Combustion requires a lot of oxygen which is often not available in immediate supply, so incomplete combustion occurs too leading to smoky flame.
Describe friedel crafts alkylation of benzene. What must be added to benzene, what conditions are used and what is the product, and side product.
You add R-X, AlCl3 catalyst under reflux. You form C6H5R and HX.
Describe friedel crafts acylation of benzene. What must be added to benzene, what conditions are used and what is the product, and side product.
You add RCOCl. AlCl3 catalyst under reflux. Then heat. You form C6H5COR and HCl.
Describe halogenation of benzene. What conditions are needed. What are the products and side products.
Add a halogen at room temp with AlCl3/FeBr3 catalyst. You get a halobenzene and HX.
The nitration of benzene occurs in two stages. State what happens in each stage and the ideal temperature to carry out this reaction.
Stage 1: HNO3 + H2SO4 (both concentrated) —> H2NO3+ and HSO4-
Stage 2: H2NO3+ decomposed to NO2+ and H2O.
NO2+ goes on to attack the benzene.
Must happen at temperatures below 55*c
Describe the bromination of phenol. What is required, state conditions. What is the name of the product and side product.
Add Br2 and shake. You form 2,4,6 - tribromophenol and side product is HBr.
Describe the synthesis of aspirin, what reactants are needed and what are the conditions. State the product and side product.
Salicylic Acid reacts with Ethanoic Anhydride. Conditions are a few drops of H3PO4, 50*c. You form aspirin and ethanoic acid.
Give 3 ways aliphatic amines can be produced from haloalkanes.
Method 1: add LiAlH4 in dry ether and dilute acid to a nitrile to reduce it to a primary amine. This method is not commonly used in industry because LiAlH4 is expensive.
Method 2: add H2 in the presence of Pt/Ni catalyst, use high temperature and pressure for the reaction to form a primary amine. More used in industry as it’s cheaper.
Method 3: add ethanolic ammonia, heat. You form amines and a mixture of primary, secondary, tertiary and quaternary ammonium salts.
How do you make an aromatic amine from nitrobenzene. State conditions, main product and side product.
Add 6[H]. Conditions are: tin, concentrated HCl, reflux and add some NaOH. Main product is a phenylamine and the side product is 2H2O.
How can you make an ammonium salt?
React an amine and an acid together.
What reaction occurs when you dissolve a smaller amine? What pH solution is formed and why?
Reversible reaction. Amine + H2O <=> alkyl ammonium ions + OH- ions. You form an alkaline solution due to the presence of OH- ions.
Name the two ways of producing amides. State any conditions, reactants, and products.
- Adding concentrated ammonia to an Acyl chloride produces a primary amide and HCl.
- Adding concentrated primary amine to Acyl chloride forms an n-substituted amide and HCl as the side product. A further reaction can occur: primary amine + HCl to give a solid white precipitate of ammonium chloride salt.
Both reactions occur at room temperature.
How can you make a Grignard reagent? State conditions and products.
React RX with Mg, And dry ether under reflux. You form RMgX.
What happens when a Grignard reagent is added to CO2? State any conditions needed for this reaction to occur and products.
Conditions are dry ether and dilute HCl and you form a carboxylic acid and MgBrCl.
What happens when a Grignard reagent is reacted with a carbonyl compound, state any conditions needed for this reaction to occur and any products.
You need to have dry ether and dilute HCl for this reaction to occur. You form an alcohol and MgBrCl.
