Category Archives: 3.3 Haloalkanes

Mechanism of ozone depletion by haloalkanes

Ozone, formed naturally in the upper atmosphere, is beneficial because it absorbs ultraviolet radiation. Chlorine atoms are formed in the upper atmosphere when ultraviolet radiation causes C–Cl bonds in chlorofluorocarbons (CFCs) to break. Chlorine atoms catalyse the decomposition of ozone and contribute to the hole in the ozone layer. Appreciate that results of research by different groups in the scientific community provided evidence for legislation to

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Nucleophilic substitution mechanism of haloalkanes

Haloalkanes contain polar bonds. Haloalkanes undergo substitution reactions with the nucleophiles OH–, CN– and NH3 Students should be able to: • understand and outline the mechanism of nucleophilic substitution in primary haloalkanes • explain why the carbon–halogen bond enthalpy influences the rate of reaction. Assessment and practical opportunities Students could follow instructions when carrying out test-tube hydrolysis of halogenoalkanes to show their relative rates of reaction. Students

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