This question is about hydrocarbons and the uses of hydrocarbons - AQA - GCSE Chemistry Combined Science - Question 4 - 2022 - Paper 2

A hydrocarbon is a molecule made up of carbon and hydrogen atoms only.

The complete equation for the reaction is:
$C_{n}H_{2n+2} \rightarrow C_{5}H_{10} + 2C_{2}H_{4}$

One of the products of cracking, such as ethylene ($C_{2}H_{4}$), is in high demand because it is highly flammable, making it useful as a fuel, and it serves as a key raw material for producing polymers, such as plastic.

The sustainability of wooden and plastic window frames can be evaluated by considering various factors:

Environmental Impact

• Production: Plastic production uses hydrocarbons derived from non-renewable crude oil, which contributes to greenhouse gas emissions and global warming. In contrast, wood is a renewable resource, though its sustainability depends on responsible forestry practices.
• Greenhouse Gases: The production of plastic releases more greenhouse gases than wood, contributing to air pollution and climate change.
• Waste: Plastic frames contribute significantly to landfill issues as they take a long time to decompose, while wood can be more easily broken down and can sometimes be recycled.

Economic Factors

• Cost: Wooden frames often have lower lifetime maintenance costs compared to plastic, which can require more resources for upkeep.
• Energy Consumption: The total energy consumption for the production and disposal of plastic frames is generally higher than for wooden frames, making wooden frames more economical in the long run.

Judgment

In conclusion, while both materials have environmental and economic impacts, wooden frames generally present a more sustainable option due to their renewable nature, lower greenhouse gas emissions, and overall reduced energy consumption in comparison to plastic frames.