Question 18 – Halogenoalkanes - AQA Chemistry Questions

This question is about the ozone layer and atmospheric chemistry.

Describe how the stratospheric ozone layer protects living organisms on Earth.

Hydrobromofluorocarbons (HBFCs) can also release bromine atoms in the upper atmosphere. Describe how a molecule of bromodifluoromethane ( $CHF2Br\text{CHF}_2\text{Br}$ ) forms bromine atoms in the stratosphere.

Write two equations to show how bromine atoms ( $Br∙\text{Br}^\bullet$ ) catalyse the decomposition of ozone ( $O3\text{O}_3$ ).

HBFCs can be synthesised by the free-radical substitution of fluoroalkanes. In the mechanism to make the HBFC $CHBrF2\text{CHBrF}_2$ from difluoromethane ( $CH2F2\text{CH}_2\text{F}_2$ ), two incomplete propagation steps are shown below.

Complete each step in the mechanism: $......................................................→∙CHF2+HBr\text{......................................................} \rightarrow {}^\bullet\text{CHF}_2 + \text{HBr}$ $∙CHF2+Br2→......................................................{}^\bullet\text{CHF}_2 + \text{Br}_2 \rightarrow \text{......................................................}$

Give the name of the type of step represented by both of these equations.

This question is about the ozone layer and atmospheric chemistry.

Describe how the stratospheric ozone layer protects living organisms on Earth.

Write two equations to show how bromine atoms ( $Br∙\text{Br}^\bullet$ ) catalyse the decomposition of ozone ( $O3\text{O}_3$ ).

Give the name of the type of step represented by both of these equations.

Halogenoalkanes

Question 12

Halogenoalkanes

Question 12

Halogenoalkanes

Question 12

Halogenoalkanes Questions

Halogenoalkanes

Question 12

Halogenoalkanes Questions