1. Organic chemistry
Question
Section B

2. Answer: general formula / differ by CH₂/
same functional group / similar chemical properties / gradation in physical properties / similar method of preparation ANY ONE: (5)
Section B Q9(a) 2006

3. Answer: glass wool / roc(k) sil (3)
(ii) Identify the solid B which is used to keep the ethanol at the end of the test tube. (3)
Answer: glass wool / roc(k) sil (3)
Section B Q9(b)

4. (iii) What precaution should be observed when heating is stopped
(iii) What precaution should be observed when heating is stopped? Why is this necessary? (6)
Answer: remove the delivery tube from the trough of water / disconnect tube (stopper) from test tube / dismantle the apparatus (3) WHY: to prevent suck-back (3)
Section B Q9(b)

5. (iv) Give one major use of ethene gas. (3)
Answer: manufacture of polythene (polyethene, plastic) / make ethane-1,2-diol (ethylene glycol, antifreeze) / make polyester (terylene) / make PVC / make ethanol / ripening fruit / make poly(phenylethene) {polystyrene) (3)
Section B Q9(b)

6. Answer
Section B Q9(C)

7. Section B Q2(C)

8. Answer
Section B Q9(d)

9. Section B Q9(d)