Explain the different explain how hydroxide ions act as a The concurrent substitution and between substitution in elimination reactions elimination reactions of a and elimination predict the products of competing halogenoalkane (e.g. 2-bromopropane reactions and why substitution and elimination with potassium hydroxide). elimination reactions reactions between hydroxide ions Students should be able to: explain occur instead of and halogenoalkanes the role of the reagent as both substitution reactions. Explain the mechanism nucleophile and base; outline the of the reaction using mechanisms of these reactions. curly arrows. 7 Ozone depletion 3.3.3.3 Ozone depletion Research opportunity: 13.3 describe the role of naturally formed Students investigate formed naturally in the upper Describe the role of ozone in the upper atmosphere the role of chemists in the atmosphere, is beneficial because it ozone and evidence for use equations to explain how introduction of legislation to absorbs ultraviolet radiation. its depletion. Use chlorine atoms catalyse the ban the use of CFCs and in reactions to explain decomposition of ozone finding replacements. Chlorine atoms are formed in the upper how it is being explain the role of the scientific atmosphere when ultraviolet radiation depleted. Explain some community in providing evidence for causes C–Cl bonds in of the measures used legislation to ban the use of CFCs as chlorofluorocarbons (CFCs) to break. to restore its solvents and refrigerants and find concentrations alternatives Chlorine atoms catalyse the decomposition of ozone and contribute to the formation of a hole in the ozone layer. Appreciate that results of research by chemists provided evidence for legislation to ban the use of CFCs as solvents and refrigerants. Chemists have now developed alternative chlorine-free compounds. Students should be able to: use equations, such as the following, to explain how chlorine atoms catalyse decomposition of ozone:
Explain the different between substitution and elimination reactions and why elimination reactions occur instead of substitution reactions. Explain the mechanism of the reaction using curly arrows. explain how hydroxide ions act as a in elimination reactions predict the products of competing substitution and elimination reactions between hydroxide ions and halogenoalkanes The concurrent substitution and elimination reactions of a halogenoalkane (e.g. 2-bromopropane with potassium hydroxide). Students should be able to: explain the role of the reagent as both nucleophile and base; outline the mechanisms of these reactions. 7 Ozone depletion Describe the role of ozone and evidence for its depletion. Use reactions to explain how it is being depleted. Explain some of the measures used to restore its concentrations describe the role of naturally formed ozone in the upper atmosphere use equations to explain how chlorine atoms catalyse the decomposition of ozone explain the role of the scientific community in providing evidence for legislation to ban the use of CFCs as solvents and refrigerants and find alternatives 3.3.3.3 Ozone depletion 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 formation of a hole in the ozone layer. Appreciate that results of research by chemists provided evidence for legislation to ban the use of CFCs as solvents and refrigerants. Chemists have now developed alternative chlorine-free compounds. Students should be able to: use equations, such as the following, to explain how chlorine atoms catalyse decomposition of ozone: Research opportunity: Students investigate the role of chemists in the introduction of legislation to ban the use of CFCs and in finding replacements. 13.3
Chemistry%20SoW%20Year%201.docx