Organic Chem AfL

1 Name:______________________________( ) Class:_________ Date:___________ An Introduction to Organic Chemistry AFL TEST Multiple-Choice Questions (10 marks) 1. Which statement about the members of a homologous series is not true? A They have the same functional group. B They undergo similar chemical reactions. C They have the same molecular mass. D There is a gradual change in their boiling points down the series. ( ) 2. Petroleum can be separated by fractional distillation because its constituents _____________. A are immiscible B have different densities C are highly flammable D have different boiling points ( ) 3. Which of the following fractions of petroleum has the highest boiling point? A Diesel B Kerosene C Bitumen D Petroleum gas ( ) 4. The table below shows the boiling point ranges of four fractions collected from the fractional distillation of petroleum. Which fraction contains the smallest molecules? Fraction Boiling point range/°C A 40–75 B 150–240 C 220–250 D 300–350 ( ) 25

2 5. Which of the following are arranged in order of increasing boiling points? A Kerosene, petrol, diesel, bitumen B Bitumen, diesel, kerosene, petrol C Petrol, diesel, kerosene, bitumen D Petrol, kerosene, diesel, bitumen ( ) 6. At which outlet of the fractionating column below is the fuel used in gas cookers collected? ( ) 7. Which of these fractions has the most number of carbon atoms per molecule? A Naphtha B Petroleum gas C Petrol D Lubricating oil ( ) 8. The main constituent of natural gas is _____________. A butane B ethane C methane D petroleum gas ( ) 9. Some substances obtained from the distillation of petroleum are listed in order of decreasing boiling points. bitumen, P, diesel, Q, naphtha, R, petroleum gas Which row correctly identifies P, Q and R? P Q R A lubricating oil kerosene petrol B lubricating oil petrol kerosene C petrol kerosene lubricating oil D petrol lubricating oil kerosene ( ) A B C D

3 10. Which of the following statements is true? A Petroleum can be separated by simple distillation. B Natural gas is a renewable source of energy. C Biodiesel is an alternative fuel to petroleum. D Biogas is produced when organic matter decays in air. ( ) Structured Questions (15 marks) 11. The structures of three compounds are shown below. Complete the table. [6] Compound Structure Functional group Name of compound X H H | | H – C = C – H Y H H O | | || H – C – C – C – O – H | | H H Z H | H – C – O – H | H 12. (a) Which petroleum fraction (i) is used as a chemical feedstock; [1] (ii) is the most volatile? [1]

4 (b) Describe how petroleum is separated into useful fractions by fractional distillation. [4] 13. The table below shows the approximate composition of petroleum from various sources expressed in percentage by mass. Source Naphtha Petrol/Paraffin Diesel/Lubricating oil Middle East 20 34 46 Nigeria 24 38 38 North Africa 30 38 32 Venezuela 2 18 80 Suggest reasons why the price per barrel of oil is greatest for North African petroleum and least for Venezuelan petroleum. [3]