Page 05 9. Which of the following is not a step in a free radical chain reaction? A Activation B Initiation C Propagation D Termination 10. Which of the following is an isomer of ethyl propanoate (CH3CH2COOCH2CH3)? A Methyl propanoate B Pentan-2-one C Pentanoic acid D Pentane-1,2-diol 11. Essential oils are A non-water soluble, non-volatile compounds B non-water soluble, volatile compounds C water soluble, non-volatile compounds D water soluble, volatile compounds. 12. The enthalpy of combustion of a hydrocarbon is the enthalpy change when A one mole of a hydrocarbon burns to give one mole of water B one mole of a hydrocarbon burns to give one mole of carbon dioxide C one mole of a hydrocarbon burns completely in oxygen D one mole of a hydrocarbon burns in one mole of oxygen. 13. Which of the following is the strongest reducing agent? A Fluorine B Lithium C Calcium D Iodine [Turn over Page 06 14. TiCl4 + 2Mg ↓ 2MgCl2 + Ti mass of mass of mass of mass of one mole one mole one mole one mole = 189·9 g = 24·3 g = 95·3 g = 47·9 g The atom economy for the production of titanium in the above equation is equal to A 47 9 100 189 9 24 3 × + · · · B ( ) 47 9 100 189 9 2 24 3 × × + · · · C 95 3 47 9 100 189 9 24 3 + × + · · · · D ( ) 2 47 9 100 189 9 24 3 × × + · · · 15. The vitamin C content of a carton of orange juice was determined by four students. Each student carried out the experiment three times. Experiment 1 (mg/100 cm3) Experiment 2 (mg/100 cm3) Experiment 3 (mg/100 cm3) Student A 30·0 29·0 28·0 Student B 26·4 26·6 26·8 Student C 26·9 27·0 26·9 Student D 26·9 26·5 26·9 The most reproducible results were obtained by A Student A B Student B C Student C D Student D.