Industrial Chemistry Flashcards
Discuss the issues associated with shrinking world resources with regard to one identified natural product that is not a fossil fuel, identifying the replacement materials used and/or current research in place to find a replacement for the named material.
Rubber is an important resource used in tyres, belting, hoses and footware.
Rubber is elastic, touch, adhesive and an electrical insulator
Natural rubber is made from the sap of rubber trees and it can take 6-7 years before it is available to be harvested
World War II interrupted natural rubber suplies, and cause an increase in demand (for militarry vehicle tyres)
German and US scientists developed synthetic polymers to replace rubber.
After WWII, demand for rubber could not be met by natural rubber tree plantations, and thus synthetic rubbers dominated the market instead.
Outline three uses of sulfric acid in industry
- Manufacture of superphosphate fertiliser.
- Catalyst in the hydration of ethene to make ethanol
- Lead acid car batteries (electrolyte)
- Vicose rayon manufacturing
Describe the process used to extract sulfur from mineral deposits
The Frasch Process
- Superheated high pressure water is firstly pumped down the centre of three concentric pipes into the sulfur deposits
- This melts the sulfur and forms an emulsion
- Compressed air is then blown down the inner pipe, which forces the water-sulfur emulsion up the middle pipe where it is collected.
- When the mixture is cooled, solid sulfur separates from liquid water, obtaining 99.5% pure sulfur.
Identify the properties of sulfur which allow its extraction
Relatively low melting point – superheated water is enough to melt it
Low density – can be forced up by compressed air
Insoluble in water – separates out on solidifying
Analyse potential environmental issues that may be associated with sulfurs extraction.
Caving-in of the deposit gap (earth subsidence) due to removal of sulfur beds
Oxidation of sulfur to sulfur dioxide
Reduction of sulfur to hydrogen sulphide
Thermal pollution due to superheated water being deposited into local waterways
What are the conditions needed for the production of sulfur dioxide
- Dry oxygen enriched air by dehydrating agent (sulfuric acid)
- Recycled heat that is generated to melt the sulfur or electricity production to ensure heat energy is not wastes
What are the conditions needed for the production of sulfur trioxide
- Compromised temperature of 450-600 decrees to allow high yield and fast reaction rate
- A catalyst to increase the reaction rate.
- Increase pressure to push equilibrium to the right
- Excess oxygen to push equilibrium to the right and increase yield
Describe sulfuric acid as an oxidisng agent
Sulfuric acid is a relatively strong oxidant. It causes something to be reduced and is therefore an electron acceptor.
Describe sulfuric acid as a dehydrating agent
Sulfuric acid has a very strong affinity for water: it absorbs water from mixtures such as moist air and forms an aqueous solution.
Gases such as oxygen, nitrogen and carbon dioxide can be dried by bubbling them through concentrated sulfuric acid.
Concentrated sulfuric acid is also used as a dehydrating agent to remove water from compounds. It removes water from carbohydrates and other organic substances.
For example, if concentrated sulfuric acid is added to sugar (sucrose), the hydrogen and oxygen atoms are removed from the sucrose molecule to form water leaving behind carbon.
identify and describe safety precautions that must be taken when using and diluting concentrated sulfuric acid
- Adding water to concentrated sulfuric acid is very dangerous as the heat produced by hydration can cause the acid to boi and spit.
Therefore small quantities of acid is needed to be added to large quantities of water
Can cause skin to burn and char as it is a storng dehydrating agent
Therefore safety clothing must be worn
Have a suply of sodium carbonate or hydrogen carbonat to neutralise any spils
