HCI 2021 Prelim Paper 1 Questions

This document consists of 14 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 20S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 17 September 2021 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Complete the information on the Answer Sheet as shown below. There are thirty questions on this paper. Answer all questions. For each question, there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate.

© Hwa Chong Institution 2021 9729 / 01 / C2 Prelim 2021 2 1 The successive ionisation energies of the gaseous ion, G+, are given in the table below: number of electrons removed 1 2 3 4 5 6 ionisation energy/ kJ mol –1 1907 2914 4964 6274 21 267 25 431 Which group in the periodic table does G belong to? A 14 B 15 C 16 D 17 2 In which of the following pairs of compounds would the second compound have a higher boiling point than the first compound? 1 HCHO, CH3OH 2 BF3 , AlF3 3 CH3CH2CH2CH2CH3, C(CH3)4 A 1 and 2 B 1 and 3 C 2 and 3 D 1, 2 and 3 3 Information about the properties of some compounds are given below. density / g cm−3 ice 0.931 water 0.997 boiling point / °C HF 19.5 NH3 −33.3 2-nitrophenol 216 4-nitrophenol 279 Which statement about the hydrogen bonding in these compunds is incorrect? A HF has a higher boiling point than NH3 because each HF molecule can form more hydrogen bonds on average compared to each NH3 molecule. B Hydrogen bonds between molecules of H2O in ice causes the density of ice to be lower than that of water. C When CH3CO2H is dissolved in benzene, hydrogen bonding between two molecules of CH3CO2H causes the Mr to double from 60 to 120. D The boiling point of 2-nitrophenol is lower than 4-nitrophenol due to the presence of intramolecular hydrogen bonding in 2-nitrophenol.

© Hwa Chong Institution 2021 9729 / 01 / C2 Prelim 2021 3 4 Which graph will not have the same shape for a fixed mass of gas compared to the rest? (All values are measured in SI units.) A pV against T C pV against V at constant T B p against density at constant T D p against 1/V at constant T 5 When a liquid hydrocarbon was burnt in 100 cm3 of excess oxygen gas, the gaseous mixture contracted by 15 cm3. On passing the resultant gaseous mixture through aqueous sodium hydroxide, there was a further contrac