PAPER 2 WRONG QUESTIONS

Question 1

why is it necessary to convert long-chain alkanes into short-chain alkanes? (2 marks)

Answer 1

1. greater demand for shorter chain alkanes than long chain alkanes
2. more long chain alkanes than are needed

Question 2

what forms at each electrode in the electrolysis of copper sulfate solution? (2 marks)

Answer 2

positive- bubbling/ effervescence
negative- brown solid

Question 3

explain why the copper sulfate solution becomes paler blue in electrolysis: (2 marks):

Answer 3

1. blue colour is caused by copper ions
2. copper ions are removed from the solution

Question 4

colour of methyl orange at the beginning and end of titration (2 marks):

Answer 4

from YELLOW to ORANGE

Question 5

temperature and pressure needed for the fermentation of ethene (2 marks):

Answer 5

1. 300 degrees celsius
2. 60-70 atmospheres

Question 6

describe how a pure, dry sample of the insoluble salt, barium sulfate, could be made from the two solids sodium sulfate and barium chloride (5 marks):

Answer 6

1. dissolve each of the solids in water
2. mix the two solutions together
3. filter the mixture
4. wash the precipitate with water
5. crystallisation