C7 - Further Chemistry Flashcards
Fine chemicals
Chemicals which are made on a small scale in chemical labs.
Name 4 fine chemicals
- Drugs
- Flavourings
- Preservatives
- Fragrance
What 6 things do chemists have to do when developing a new chemical product?
- Research catalysts for new processes
- Follow standard procedures
- Carry out a titration
- Scale up production
- Interpret results
- Carry out quality assurance
Why does the government have laws and regulations on chemicals? (2)
- To protect people; workers, customers and the populace in general
- To protect the environment from permanent or unsustainable damage
What are the 7 stages of chemical synthesis?
- Choosing a reaction
- Risk assessment
- Working out quantities
- Carrying out reaction in optimum conditions
- Separating the products and handling by product disposal/ use
- Purifying the product
- Measuring yield and chemical the purity of the product.
What 7 criteria do the sustainability of a chemical process rely on?
- Atom economy
- The use of renewable feedstock
- Energy inputs and outputs
- Health and safety risks
- Waste prevention
- Environmental impact
- Social and economic benefits
What is the formula to calculate atom economy?
Mass of atoms in the useful product / total mass of products x100
What is the formula for percentage yield?
Actual Yield (What you get) / Theoretical Yield (What you should get) x100
Social benefits of Green chemistry: (3)
- Cleaner air quality
- Cleaner buildings
- Improved water quality in rivers & lakes
Economic benefit of Green chemistry:
•reduced energy costs
How are Catalysts useful? (3)
They:
•Reduce the activation energy so the reaction can happen at a lower temperature and pressure
•Can improve atom economy
•Are not used up so make processes more sustainable
What are the optimum conditions for Enzyme Catalysts to work?
pH: about 7.4
Temperature of 37 Degrees centigrade
Bulk chemicals
Chemicals make on a large scale at an industrial level.
Name the 3 main properties of Alkanes:
- They have single covalent bonds and are saturated hydrocarbons
- They don’t react with water because the bonds are strong and unreactive
- The burn in air to produce Carbon Dioxide and Water
What is the general formula for Alkanes?
CnH2n+2
What are the names and formulas of the first 4 Alkanes?
Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
How is the test for a double bond carried out? (2)
- Add bromine water
2. The alkene will become colourless because of the double bond
What are the bonds of Alkenes like?
- They have reactive C=C double bonds
* They are Unsaturated
What is the general formula for Alkenes?
CnH2n
What is the general formula for Alcohols?
Cn H2n+1 OH
Name the first four alcohols:
Methanol CH3OH
Ethanol C2H5OH
Propanol C3H7OH
Butanol C4H9OH
Name 2 uses of Methanol
- As a chemical feedstock
* In the manufacture of cosmetics
Name 3 uses of Ethanol
- As a chemical feedstock
- Solvent
- Fuel
What are the properties of Shorter chain alcohols:(3)
- Low boiling points
- Weak intermolecular forces
- Very soluble in water
What are the properties of Longer chain alcohols:(3)
- High boiling points
- Strong intermolecular forces
- Less soluble (float on top of water)
What are the products of the reaction between Alcohols and Sodium?
Salt and Hydrogen Gas (H2)
How does sodium react with alcohol, water and Alkanes?
- Sodium sinks in alcohols, doesn’t melt and slowly gives off hydrogen gas
- Sodium floats on water, melt, rushes around on the surface and rapidly give off hydrogen
- There is no reaction between sodium and Alkanes
Name the 3 ways Ethanol is produced?
- Synthesis
- Fermentation
- Biotechnology
What is the formula of ethanol production by synthesis?
Ethene + Steam -> Ethanol
C2H4(g) + H2O(g) -> C2H5OH(g)
What are the steps of Ethanol Synthesis? (6)
- Crude oil undergoes fractional distillation
- Long chain hydrocarbons (Alkanes) are vaporised and then cracks using a catalyst and heat
- The molecules are purified using fractional distillation
- The Ethene that is produced can be used as a feedstock and the remaining water is removed
- Ethene is reacted with steam at a high temperature and pressure with a catalyst to product ethanol
- Any unreacted products are recycled
What are the 3 steps of producing ethanol by fermentation?
- Water and yeast are mixed with natural sugars at just above room temperature.
- Enzymes found in the yeast catalyse the formation of ethanol and carbon dioxide.
- The carbon dioxide is allowed to escape from the reaction vessel but air is prevented from entering it.
What is the formula for Ethanol Fermentation?
C6H12O6(aq) -> 2C2H5OH(aq) + 2CO2(g)
What limits the concentration of ethanol when the fermentation method is used? (2)
- The amount of sugar in the mixture
* The fact that above a certain concentration the ethanol kills the yeast