Alcohols Flashcards
What are the uses of ethanol?
- Alcoholic drinks
- To make solvents
- Fuel for cars
How is ethanol made?
Fermentation
Why does the temperature have to be kept between 25-50 c during fermentation?
Its the optimum temperature for the enzymes in the yeast
What type of reaction turns ethene into ethanol?
A reversible reaction
What are the advantages of producing ethanol via hydration?
- Its quicker
- Ethene is available in large quantities
- Its continuous
- 100% atom economy
What are the disadvantages of producing ethanol via fermentation?
- Slow batch process
- Ethanol has to be purified first
- Purification is expensive and uses energy
What are the advantages of producing ethanol via fermentation?
Higher percentage yield
What is the difference between hard and soft water?
- Soft water lathers well with soap
- Hard water doesn’t lather well
What causes hardness in water?
Calcium and magnesium ions from dissolved salts
What is permanent water hard water?
Hard water which cant be destroyed by boiling and is caused by dissolved substances such as calcium sulfate
What is temporary hard water?
Hard water that is caused when rainwater comes into contact with calcium carbonate and can be removed by boiling
What affects the hardness of water?
What rocks the water has flowed over
What is limescale?
Deposited calcium carbonate
How can you measure water hardness?
Adding soap to water and recording how much lather is produced after being shaken for five seconds
How can you remove hardness from water?
- Adding washing soda
- Passing it through an ion-exchange column
