Chemistry Using Resources

What are natural resources used for?

• Providing warmth

• Shelter

• Food

• Transport

Define potable water.

Water that is safe for human consumption.

What are common methods to produce potable water?

• Filtration

• Sterilization

How can seawater be made potable?

Through desalination processes like distillation or reverse osmosis.

Why is desalination not commonly used?

• Requires large amounts of energy.

• Expensive to operate.

What is a Life Cycle Assessment (LCA)?

Evaluation of the environmental impact of a product throughout its life stages.

What stages are considered in an LCA?

• Extracting and processing raw materials

• Manufacturing and packaging

• Use and operation during lifetime

• Disposal at end of life

Why can LCAs be subjective?

Assigning numerical values to environmental impacts involves value judgments.

How can LCAs be misused?

Selective LCAs might support biased claims, especially in advertising.

What are ways to reduce resource use?

• Recycling materials

• Reusing products

• Reducing consumption

How does recycling benefit the environment?

• Conserves raw materials

• Reduces energy consumption

• Decreases waste production

What is corrosion?

Destruction of materials due to chemical reactions with environmental substances.

What conditions are necessary for iron to rust?

Presence of both air and water.

How can corrosion be prevented?

Applying coatings like:

• Grease

• Paint

• Electroplating

What is sacrificial protection?

Using a more reactive metal to prevent corrosion of a less reactive one.

What are alloys?

Mixtures of metals with other elements to enhance properties.

Why are alloys stronger than pure metals?

Different atom sizes disrupt the metal lattice, hindering layer movement.

What is the difference between thermosoftening and thermosetting polymers?

• Thermosoftening: Soften on heating; can be reshaped.

• Thermosetting: Do not soften on heating; retain shape.

How does the structure of polymers affect their properties?

• Cross-linked polymers are rigid.

• Linear polymers can slide, making them flexible.

What are composites and give examples and their uses?

Materials made from two or more different substances, combining properties.

• Fiberglass: Boats, surfboards

• Concrete: Construction

What is the Haber Process used for?

Manufacturing ammonia for nitrogen-based fertilizers.

What are the raw materials for the Haber Process?

• Nitrogen (from air)

• Hydrogen (from natural gas or other sources)

Describe the conditions used in the Haber Process.

• Temperature: ~450°C

• Pressure: ~200 atmospheres

• Catalyst: Iron

Why is the Haber Process considered a dynamic equilibrium?

• Forward and backward reactions occur simultaneously once equilibrium is reached.

What happens to the ammonia produced in the Haber Process?

• It liquefies upon cooling and is removed.

How is unreacted nitrogen and hydrogen treated in the Haber Process?

Recycled back into the system.

What are NPK fertilizers?

• Fertilizers containing compounds of nitrogen, phosphorus, and potassium.

How are NPK fertilizers produced industrially?

Using various raw materials in integrated processes to create formulations with appropriate nutrient percentages.

Why are NPK fertilizers important in agriculture?

• Enhance soil fertility

• Improve crop yields

What is the significance of using formulations in NPK fertilizers?

Ensures the correct balance of nutrients for specific plant needs.

How does the use of fertilizers impact the environment?

Can lead to waterway pollution through runoff.

What are alternative methods to synthetic fertilizers for soil fertility?

• Crop rotation

• Use of organic compost

Why is the Haber Process considered a compromise between rate and yield?

• Higher temperatures increase reaction rate but favor the reverse reaction.

• High pressures favor ammonia production but are costly and hazardous.

How does the choice of catalyst affect the Haber Process?

• Iron catalyst increases reaction rate without affecting equilibrium position.

What is phytomining and how does it work?

• Using plants to extract metals from ores.

• Plants absorb metal ions from soil and concentrate them in their tissues.

• Metals are extracted by burning plants and collecting metals from ashes.

What are the advantages and disadvantages of phytomining?

• Advantages:

  • Environmentally friendly and sustainable.

  • Low-cost method for extracting metals from low-grade ores.

• Disadvantages:

  • Slow process, takes time for plants to grow.

  • Not efficient for large-scale operations.

What is bioleaching and how does it work?

• Using bacteria or microorganisms to extract metals from ores.

• Bacteria produce acids that break down ores, releasing metal ions into solution.

What are the advantages and disadvantages of bioleaching?

• Advantages:

  • Environmentally friendly.

  • Works well on low and medium-concentration ores.

• Disadvantages:

  • Slow process.

  • Requires specific conditions for bacteria to thrive.

What are the environmental benefits of phytomining and bioleaching?

• Both reduce the need for traditional mining, preventing environmental damage like soil erosion and habitat destruction.

• Both methods have lower energy requirements compared to traditional mining.