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Flashcards in Reaction conditions questions Deck (11):
1

Conditions required for the halogenation of alkanes?

- Temperatures of 300*C or presence of ultraviolet radiation.
- No more energy required for the rest of the process to occur.

2

Give the conditions for the addition reactions of ethene with Cl2, HCl, H2, H2O.

- 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

Conditions for the hydration of ethene industrially?

- 60 atmospheres.
- Temperature of 300*C
- H3PO4 catalyst.

4

Conditions for fermentation

- Concentration of ethanol in reaction mixture does not reach past 14% because its toxic to yeast.
- Low temperatures 25*C-37*C
- 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

What colour does acidified dichromate go when in an oxidation reaction?

- Orange to green.

6

Conditions to make aldehydes?

- 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

Conditions to make a carboxylic acid?

- Stronger heating(than with an aldehyde) with excess acidified dichromate.
- Heated under reflux.

8

Conditions to make ketones?

- Reflux
- Heating

9

Conditions for esterification?

- Presence of acid catalyst (H2SO4)
- Heating (place boiling tube with reaction mixture into hot water bath) for 5 minutes.

10

Conditions for the dehydration of an alcohol?

- Acid catalyst (H3PO4, H2SO4)
- Heated under reflux for 40 minutes.

11

Conditions of hydrolysis?

- Halogenoalkane heated with aqueous silver nitrate, with ethanol added.
- water in the mixture acts as a nucleophile.
- Ethanol acts as a common solvent.