Resources & Sustainability (OCR GCSE Chemistry A, Combined (Gateway Science Suite)): Revision Notes

10.1.1 Resources & Sustainability

What's in Our Water?

Importance of Water:

• Water is essential for life. The quality of life depends on the availability of clean water.
• In the UK, rainwater is treated to make it drinkable.

Composition of Water:

• Water is a fantastic solvent that dissolves two main types of solutes:
  • Ions: As water flows over the ground, it picks up various ions from minerals, such as Mg²⁺, Ca²⁺, Na⁺.
  • Gases: Rainwater dissolves gases like oxygen (important for marine life) and carbon dioxide (which lowers the pH of water).

Contaminants in Water:

• Water also picks up microorganisms (natural pollutants) like bacteria and viruses.
• Additionally, it may contain man-made pollutants such as fertilisers, pesticides, and household and industrial waste.

Sustainable Water Supply

Water Availability:

• Although Earth has plenty of water, only a small fraction is safe for drinking.
• With a growing population and developing industries, the demand for water is higher than ever.

Why Do We Need Water?:

• Industrial Use: Water is needed in factories for cooling machinery.
• Hygiene: We need water for personal hygiene, such as washing clothes and keeping clean.
• Drinking Water: Water is essential for drinking and maintaining health.
• Agriculture: Water is necessary on farms to grow food.

Water Usage:

• On average, people in the UK use 150 litres of water per day.
• Water comes from natural underground storage, rivers, and various reservoirs.
• Drought can occur during dry conditions when there is insufficient rain to replenish water supplies.

Sustainability and Water Shortages:

• Water Shortages: These occur when the demand for water exceeds the supply, posing a threat to life and the environment.
• Future Risks: Climate change may increase the risk of water shortages, making the efficient use of water even more important.

Ways to Conserve Water:

• Use washing machines and dishwashers only when they are full.
• Take showers instead of baths to use less water.
• Reuse waste water for plants and car washing.
• Repair dripping taps to prevent water waste.
• Avoid letting water run unnecessarily, such as when brushing teeth.