2023 BBSS Chem Prelims P1

Name: ………………………………………. Index no: ……… Class: ……..… READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and class on the Answer Sheet, and in the spaces provided at the top of this page. There are forty 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. A copy of the Periodic Table is printed on page 15. The use of an approved scientific calculator is expected, where appropriate. This document consists of 15 printed pages. Bukit Batok Secondary School ‘O’ LEVEL PRELIMINARY EXAMINATIONS 2023 SECONDARY 4 EXPRESS CHEMISTRY Paper 1 Multiple Choice 6092/01 23 AUG 2023 1105 – 1205 1 hour Additional Materials: Multiple Choice Answer Sheet

BBSS/OPrelims/2023/Sec4E/6092/1 2 Applying past knowledge to new situations 1 A student studied the rate of reaction when 0.05 g of magnesium was reacted with excess acid at room temperature and pressure. Which apparatus would be suitable to measure the volume of gas produced at different times during the experiment? 1 a 50 cm3 gas syringe 2 an inverted 100 cm3 measuring cylinder filled with water 3 an inverted gas jar filled with water A 1 only B 2 only C 2 and 3 only D 1, 2 and 3 2 Under the same conditions, which of the following gases would diffuse at the same rate as ethene, C2H4? 1 carbon monoxide 2 carbon dioxide 3 ethane 4 nitrogen A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4 3 The boiling points of four substances found in air are given in the table. Air is cooled to –190 °C such that some substances condense into liquid. When the temperature is then raised, which liquid would turn into a gas first? substance boiling point /°C A B C D argon carbon dioxide nitrogen oxygen –186 –78 (sublimes) –196 –183

BBSS/OPrelims/2023/Sec4E/6092/1 3 Applying past knowledge to new situations 4 Oxygen was prepared by the decomposition of hydrogen peroxide in the presence of manganese(IV) oxide according to the equation: 2 H2O2 à 2 H2 + O2 The oxygen was collected using the set-up shown in the diagram. Which substance contaminated the first few jars of oxygen collected? A hydrogen B hydrogen peroxide C manganese(IV) oxide D nitrogen 5 Solid P conducts electricity and has a high melting point. When solid P is warmed with excess dilute hydrochloric acid, it partially dissolves leaving behind a residue. What is P? A brass B copper(II) oxide C graphite D iron aqueous hydrogen peroxide aqueous hydrogen peroxide oxygen gas jar water trough manganese(IV) oxide

BBSS/OPrelims/2023/Sec4E/6092/1 4 Applying past knowledge to new situations 6 Which of the following method(s) can be used to determine if a colourless liquid is pure? 1 Heat the liquid to saturation then allow to cool 2 Measure the boiling point of the liquid and compare with the reference value 3 Test the substance using paper chromatography A 1 and 2 only B 2 and 3 only C 2 only D 3 only 7 When aqueous sodium hydroxide is added to an aqueous solution of Y, a red-brown precipitate is observed. When nitric acid and aqueous silver nitrate is added to an aqueous solution of Y, a yellow precipitate is observed. What is Y? A FeBr2 B FeCl3 C FeCO3 D FeI3 8 The reaction between potassium hydroxide solution and dilute sulfuric acid may be represented by the following equation: 2 KOH (aq) + H2SO4 (aq) à K2SO4 (aq) + 2 H2O (l) A student found that 20 cm3 of 0.2 mol/dm3 potassium hydroxide exactly neutralised 25 cm3 of dilute sulfuric acid. What was the concentration of dilute sulfuric acid? A !"×".!!% mol/dm3 B !"×".!!×!% mol/dm3 C !%×".!!×!" mol/dm3 D !×!"×".!!% mol/dm3 9 Potassium ferrocyanide, K4[Fe(CN)6].3H2O, is an inorganic compound commonly used as an anti-caking agent for table salt. What is the percentage by mass of potassium in potassium ferrocyanide? A 9.2% B 37.0% C 37.3% D 43.1%

BBSS/OPrelims/2023/Sec4E/6092/1 5 Applying past knowledge to new situations 10 The equations for the action of heat on four metal carbonates are shown below. FeCO3 à FeO + CO2 MgCO3 à MgO + CO2 PbCO3 à PbO + CO2 ZnCO3 à ZnO + CO2 A 5.0 g sample of each metal carbonate was heated until constant mass. Which metal carbonate would produce the greatest volume of carbon dioxide? A FeCO3 B MgCO3 C PbCO3 D ZnCO3 11 The nucleus of the ion Q2– (not its real chemical symbol) contains a total of 33 particles, of which 16 possess a charge. Which statement about this ion is correct? A It contains 16 neutrons and 16 electrons. B It contains 16 protons and 16 electrons. C It contains 17 neutrons and 18 electrons. D It contains 17 protons and 18 electrons. 12 Metal nitrides are formed when metal atoms transfer electrons to nitrogen atoms. In the formation of one mole of which metal nitride do the metal atoms not transfer exactly three moles of electrons? A aluminium nitride B chromium(III) nitride C lithium nitride D zinc nitride 13 Which pair of substances have similar three-dimensional arrangements of their atoms? A diamond and graphite B diamond and silicon dioxide C lead and graphite D lead(IV) oxide and silicon dioxide

BBSS/OPrelims/2023/Sec4E/6092/1 6 Applying past knowledge to new situations 14 In a molecule of hydrogen cyanide, HCN, what is the total number of electrons present and how many of them are involved in bonding? total number of electrons number of electrons involved in bonding A B C D 14 14 26 26 4 8 4 8 15 Electrical conductivity of substances is determined by the presence of mobile charged particles. These include: 1 anions 2 cations 3 electrons Which charged particles are responsible for the electrical conductivity of copper? A 1 and 2 B 2 and 3 C 3 only D 1, 2 and 3 16 When heated with potassium hydroxide, a solution of salt X produces a gas Y that turns damp red litmus blue. After no more gas is produced, aluminium powder is added. Upon heating, gas Y is produced again. What is the formula of salt X? A Na2CO3 B NaNO3 C (NH4)2CO3 D NH4NO3 17 A dilute aqueous solution of a strong acid, HA, contains molecules of water and the ions H+ and A–. Which statement(s) is/are correct? 1 The concentration of H+ ions is equal to the concentration of A– ions. 2 The pH of the solution is greater than 7. 3 The solution contains a high concentration of HA molecules. 4 The solution also contains OH– ions. A 1 and 2 only B 1 and 4 only C 2 and 3 only D 3 and 4 only

BBSS/OPrelims/2023/Sec4E/6092/1 7 Applying past knowledge to new situations 18 Arsenic trioxide, As2O3, is an amphoteric white solid. Which reagents could be used to distinguish arsenic trioxide from solid magnesium hydroxide? 1 HNO3 2 H2SO4 3 NaOH 4 KOH A 1 or 2 B 1 or 3 C 2 or 4 D 3 or 4 19 Which pair of elements would react to form the most violent reaction? A lithium and chlorine B potassium and bromine C rubidium and fluorine D sodium and iodine 20 The nuclide notation of an atom of element R is written as R!" . Which group of the Periodic Table does R belong to? A Group 0 B Group II C Group V D Group VII 21 Copper(I) oxide reacts with sulfuric acid according to the equation Cu2O + H2SO4 à Cu + CuSO4 + H2O What is the oxidising and reducing agent in this reaction? oxidising agent reducing agent A B C D Cu2O Cu2O H2SO4 H2SO4 Cu2O H2SO4 Cu2O H2SO4 22 Which compound in aqueous solution, when added to aqueous iron(III) chloride, takes part in a redox reaction? A acidified potassium manganate(VII) B copper(II) sulf