SACE Stage 2 Chemistry, South Australia
| Front | Write the structural formula for the repeating unit of poly(ethene). |
| Back | The repeating unit of poly(ethene) is –[CH₂–CH₂]–. It forms through the polymerisation of ethene (CH₂=CH₂), where the double bond opens and links monomers in a continuous chain. |
| Front | Why is carbon suitable for extracting iron? |
| Back | Carbon is more reactive than iron and can reduce iron(III) oxide at high temperatures to produce molten iron. The carbon is oxidised to carbon monoxide or dioxide during the process. |
| Front | Explain how a biodegradable polymer is broken down. |
| Back | Biodegradable polymers contain bonds such as ester or amide linkages that can be hydrolysed by enzymes produced by microorganisms. This breakdown converts the polymer into smaller molecules like CO₂, CH₄, water, and biomass that are assimilated into the environment. |