Explain how UV light or heat breaks a halogen molecule homolytically so that each atom keeps one electron, write the initiation equation with fish-hook arrows showing single-electron movement, and contrast homolytic with heterolytic fission.
Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, , with bromine vapour, , started by ultraviolet light. The questions below treat this hypothetical route with the bond-enthalpy model and the entropy…
The rate of the reaction between compound Y and aqueous sodium hydroxide depends on the concentrations of both reactants. (i) Explain the mechanism of this reaction, using curly arrows to show the movement of electron pairs. (ii) Explain why…
(i) Concentrated sulfuric acid, , is used as the catalyst in the manufacture of propyl ethanoate. Explain how the catalyst affects the reaction. (ii) The conversion of propane into 1-bromopropane, …
Chlorinated solvents such as tetrachloromethane, , and 1,1,1-trichloroethane, , were once common in laboratories, but their production is now restricted by an international agreement. Besides climate change, state the specific…
Which radical is most likely to form when one covalent bond in bromochlorodifluoromethane, , is broken by ultraviolet light in the upper atmosphere? A. • B. • C. • D. •
(i) Iodine molecules, , undergo homolytic fission when they absorb light. Write an equation for this process, using curly arrows to show the movement of the electrons. (ii) In the presence of a suitable reagent the I–I bond can instead break…
Two observations are made about the halon in the stratosphere. Observation 1 Observation 2 Ultraviolet light breaks down to give bromine radicals rather than chlorine or fluorine radicals. A single bromine radical can destroy many…