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C6 Global challenges

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

Which pollutants form when fuels burn, and what harm do they do?

Complete and incomplete combustion of fuels, the formation of carbon dioxide, carbon monoxide, sulfur dioxide, oxides of nitrogen and particulates, and the effects of these pollutants.
A focused answer to OCR Gateway GCSE Chemistry A topic C6.2 on atmospheric pollutants, covering complete and incomplete combustion of fuels, the formation of carbon dioxide, carbon monoxide, sulfur dioxide, oxides of nitrogen and particulates, and the harmful effects of each pollutant.
9 min answer →

What is crude oil, how is it separated into useful fractions, and why is it cracked?

Crude oil as a mixture of hydrocarbons, alkanes and their general formula, the fractional distillation of crude oil, the uses of the fractions, and the cracking of long-chain hydrocarbons.
A focused answer to OCR Gateway GCSE Chemistry A topic C6.2 on crude oil and hydrocarbons, covering crude oil as a mixture of hydrocarbons, alkanes and their general formula, the fractional distillation of crude oil and the uses of the fractions, and the cracking of long-chain hydrocarbons into alkanes and alkenes.
10 min answer →

How is ammonia made in industry, and why are the conditions of the Haber process a compromise?

The Haber process for making ammonia, the compromise conditions of temperature and pressure, the use of an iron catalyst and recycling, and the use and importance of NPK fertilisers.
A focused answer to OCR Gateway GCSE Chemistry A topic C6.1 on improving processes, covering the Haber process for ammonia, the compromise conditions of temperature and pressure, the iron catalyst and recycling of unreacted gases, and the use and importance of NPK fertilisers.
10 min answer →

How do we judge the environmental impact of a product over its whole life, and why do we recycle materials?

Life cycle assessment (LCA) and its stages, the limitations of LCAs, and the advantages and disadvantages of recycling and reusing materials including metals.
A focused answer to OCR Gateway GCSE Chemistry A topic C6.1 on life cycle assessment and recycling, covering the four stages of an LCA, the limitations and value judgements involved, and the advantages and disadvantages of recycling and reusing materials including metals.
9 min answer →

What is the atmosphere made of, how did it evolve, and how do greenhouse gases drive climate change?

The composition of the atmosphere, how it evolved over time, the greenhouse gases and the greenhouse effect, and the link between human activity, climate change and the carbon footprint.
A focused answer to OCR Gateway GCSE Chemistry A topic C6.2 on the atmosphere and greenhouse gases, covering the composition of the atmosphere, how it evolved over time, the greenhouse gases and the greenhouse effect, and the link between human activity, climate change and the carbon footprint.
10 min answer →

How do we make safe drinking water, treat waste water, and extract metals sustainably?

Producing potable water by sedimentation, filtration and sterilisation, desalination by distillation and reverse osmosis, treating waste water, and the sustainable extraction of metals by phytomining and bioleaching.
A focused answer to OCR Gateway GCSE Chemistry A topic C6.2 on using the Earth's resources and water, covering producing potable water by sedimentation, filtration and sterilisation, desalination by distillation and reverse osmosis, treating waste water, and the sustainable extraction of metals by phytomining and bioleaching.
10 min answer →