GESS 3EXP CHEM EYE P1 2023

This paper consists of 14 pages including the cover page GAN ENG SENG SCHOOL End-of-Year Examination 2023 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Sec 3 Express 6092/01 11 October 2023 1 hour Additional Materials: OTAS Calculators are allowed in the examination. READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and index number on the OTAS. There are forty questions in 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 OTAS. Read the instructions on the OTAS 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 found on page 14. Total Marks 40

GESS 3EXP CHEM P2 EYE 2023 TKG 2 1 Which apparatus is most suitable for measuring 22.15 cm3 of sodium hydroxide? A beaker B burette C measuring cylinder D pipette 2 In the experimental set-up shown below, sulfur dioxide was reacted with oxygen to form sulfur trioxide by passing the mixture through heated platinised asbestos (a substance that speeds up the reaction). What is the function of concentrated sulfuric acid? A to acidify the mixture B to act as a drying agent C to act as a medium for the two reactant gases to mix D to remove impurities 3 The apparatus below shows the method to collect gas X. Which properties of gas X can be deduced? A denser than air B insoluble in water and denser than air C less dense than air D soluble in water and less dense than air

GESS 3EXP CHEM P2 EYE 2023 TKG 3 4 A mixture contains solid Y mixed with ethanol. Solid Y is insoluble in ethanol. Ethanol is an alcohol that has a boiling point of 78 ºC and Y has a boiling point of 103 ºC. Which of the following apparatus represents the best method used to obtain both solid Y and ethanol? A B C D 5 Megan performed chromatography on some ink samples. The chromatogram below was obtained. What could Megan have done wrong in her experiment? A the initial spots of ink were too small B the ink samples were insoluble in the solvent chosen C the starting line was drawn with a pen D the solvent level was above the starting line

GESS 3EXP CHEM P2 EYE 2023 TKG 4 6 The diagram shows the chromatogram obtained by analysis of a single dye. Which of the following is the correct Rf value of spot B? A 0.231 B 0.350 C 0.412 D 0.538 7 The diagram below shows the spacing of the particles in a substance Z at two different temperatures. at 232 ºC at 179 ºC Which of the following could be substance Z? melting point/ ºC boiling point/ ºC A – 21 – 9 B 160 210 C 183 253 D 194 229

GESS 3EXP CHEM P2 EYE 2023 TKG 5 8 Which option correctly describes the locations of the sub-atomic particles in an atom? proton neutron electron A in the nucleus in the nucleus orbiting the nucleus B in the nucleus in the nucleus in the nucleus C orbiting the nucleus in the nucleus orbiting the nucleus D orbiting the nucleus orbiting the nucleus in the nucleus 9 Isaac drew the electronic structure of the atom of an unknown element J as shown below. Some statements made about the mistakes that Isaac made are shown below. I the innermost shell cannot contain four electrons II the second shell cannot contain eight electrons III the electron pairs in the third shell should be placed at the top and bot tom of the shell, instead of the left and right IV the third shell must be fully filled with electrons Which of the above statement(s) correctly describes the mistake(s) Isaac has made? A I only B I and IV only C I, III, and IV only D II and III only 10 Oxygen reacts with a metal X to form an ionic compound XO. Which statement about oxygen is correct when forming this compound? A one atom of oxygen gives away one electron to an atom of X B one atom of oxygen gives away two electrons to an atom of X C one atom of oxygen receives one electron from an atom of X D one atom of oxygen receives two electrons from an atom of X 11 In which of the following sets do all the particles have the same number of electrons? A F-, Cl-, Br- B H+, He, N3- C K+, Ca2+, P3- D Na+, Mg2+, S2-

GESS 3EXP CHEM P2 EYE 2023 TKG 6 12 The bonding of sulfur trioxide is shown below. How many electrons are not involved in bonding in each oxygen atom? A 2 B 4 C 6 D 8 13 Which of the following pairs of elements forms covalent bonds? A bromine and calcium B phosphorus and oxygen C strontium and sulfur D zinc and chlorine 14 Which of the following correctly describes metallic bonding? A electrostatic forces of attraction between positive metal ions surrounded by a ‘sea of delocalised electrons’ B electrostatic forces of attraction between negative metal ions surrounded by a ‘sea of delocalised electrons’ C intermolecular forces of attraction between positive metal ions surrounded by a ‘sea of delocalised electrons’ D intermolecular forces of attraction between negative metal ions surrounded by a ‘sea of delocalised electrons’ 15 Which diagram shows a mixture of an element and a compound? A B C D 16 Which physical properties below are true of potassium oxide? A hard and brittle B hard and malleable C soft and brittle D soft and malleable

GESS 3EXP CHEM P2 EYE 2023 TKG 7 17 Which of the following structures represents lithium bromide? A B C D 18 The diagram below shows a carbon nanotube. Carbon nanotubes are made by isolating a single carbon layer from graphite. How are carbon nanotubes able to conduct electricity? A Each carbon atom forms three bonds and carbon ions formed are mobile. B One unbonded electron in each carbon atom is delocalised and mobile. C Strong covalent bonds between the carbon atoms allow electrons to easily flow through. D Weak intermolecular forces of attraction exist between carbon atoms and electrons can overcome these forces of attraction easily. 19 Dimethylglyoxime has the chemical formula (CH3CNOH)2. How many atoms does one molecule of dimethylglyoxime contain? A 5 B 8 C 10 D 16

GESS 3EXP CHEM P2 EYE 2023 TKG 8 20 The formula of iridium sulfate is Ir2(SO4)3 and that of zinc hypochlorite is Zn(ClO)2. What is the formula of iridium hypochlorite? A Ir2(ClO)2 B Ir2(ClO)3 C IrClO D Ir(ClO)3 21 Ammonia can be displaced from its salts. Which equation is correct? A Mg(OH)2 (s) + (NH4)2SO4 (aq) → MgSO4 (aq) + 2NH3 (g) + 2H2O (g) B Mg(OH)2 (s) + NH4Cl (aq) → MgCl (aq) + NH3 (g) + H2O (g) C KOH (aq) + 2NH4NO3 (s) → KNO3 (aq) + 2NH3 (g) + H2O (g) D KOH (aq) + (NH4)2SO4 (s) → KSO4 (aq) + 2NH3 (g) + H2O (g) 22 Element E has an electronic structure 2.5. Element G has an electronic structure 2.8.2. What would be the chemical formula of the compound formed between E and G? A G2E3 B G2E5 C G3E2 D G5E2 23 Mercury hydroxide reacts with phosphoric acid in the reaction below. w Hg(OH)2 + x H3PO4 → y Hg3(PO4)2 + z H2O Which values of w, x, y, and z will correctly balance the above equation? w x y z A 2 3 1 4 B 3 3 2 7 C 3 2 1 6 D 6 4 2 11 24 Which compound contains the highest percentage of nitrogen by mass? A Al(NO3)3 B Mg3N2 C NO D NO2

GESS 3EXP CHEM P2 EYE 2023 TKG 9 25 The forward reaction for the Haber process