Reaction conditions questions Flashcards
1
Q
Conditions required for the halogenation of alkanes?
A
- Temperatures of 300*C or presence of ultraviolet radiation.
- No more energy required for the rest of the process to occur.
2
Q
Give the conditions for the addition reactions of ethene with Cl2, HCl, H2, H2O.
A
- Addition of chlorine(halogenation), reaction occurs at rtp.
- Addition of HBr - hydrogen halides are gases at room temperature and are bubbled into liquid alkanes.
- Addition of hydrogen(hydrogenation) occurs at temperatures of 150*C with gaseous alkene and H2 past over nickel catalyst.
- Addition of steam(hydration) - Steam and gaseous alkene are heated to a high temperature and pressure in the presence of phosphoric acid catalyst.
3
Q
Conditions for the hydration of ethene industrially?
A
- 60 atmospheres.
- Temperature of 300*C
- H3PO4 catalyst.
4
Q
Conditions for fermentation
A
- Concentration of ethanol in reaction mixture does not reach past 14% because its toxic to yeast.
- Low temperatures 25C-37C
- Low pressures.
- In presence of no oxygen because anaerobic reaction -> occurs in the presence of no oxygen if not ethanal and ethanoic acid could be produced.
- Yeast has enzyme called zymase
- Optimum pH.
5
Q
What colour does acidified dichromate go when in an oxidation reaction?
A
- Orange to green.
6
Q
Conditions to make aldehydes?
A
- Gentle heating
- When preparing aldehydes, you will need to distil off the aldehyde from the reaction mixture as it is formed to prevent it further oxidising to a carboxylic acid.
7
Q
Conditions to make a carboxylic acid?
A
- Stronger heating(than with an aldehyde) with excess acidified dichromate.
- Heated under reflux.
8
Q
Conditions to make ketones?
A
- Reflux
- Heating
9
Q
Conditions for esterification?
A
- Presence of acid catalyst (H2SO4)
- Heating (place boiling tube with reaction mixture into hot water bath) for 5 minutes.
10
Q
Conditions for the dehydration of an alcohol?
A
- Acid catalyst (H3PO4, H2SO4)
- Heated under reflux for 40 minutes.
11
Q
Conditions of hydrolysis?
A
- Halogenoalkane heated with aqueous silver nitrate, with ethanol added.
- water in the mixture acts as a nucleophile.
- Ethanol acts as a common solvent.
