2021 SASS 4E Chem MYE Error Analysis

_______________________________________________________________________________________________________________________________________________________________________________________ Page 1 ST ANDREW’S SECONDARY SCHOOL NAME CLASS DATE CHEMISTRY 6092 Mid-Year Examination 2021 Error Analysis 1 2 3 4 5 6 7 8 9 10 Record your answers here 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 1 Which statement about nitrogen atoms is not correct? [ACSB’17] A All nitrogen atoms have the same atomic number. B All nitrogen atoms have the same chemical properties. C All nitrogen atoms have the same electronic configuration. D All nitrogen atoms have the same mass number. 2 The table below shows the number of neutrons and electrons in four particles. Particle Number of neutrons Number of electrons P 18 8 Q+ 12 10 R2- 16 10 S 22 18 Which particle is an isotope of P? [ACSB’17] A Q B R C S D None of the above

_______________________________________________________________________________________________________________________________________________________________________________________ Page 2 3 A molecule consists of three types of atoms, P, X and Y. If P is phosphorous, what could X and Y be? [ACSB’17] X Y A Al H B N Cl C O H D Si Cl 4 The diagram shows part of the structure of a salt, XY. Which statement is correct? [ACSB’17] A Each Y- ion is bonded to five X+ ions. B Each X atom is bonded six Y atoms. C The ratio of X+ to Y- is 1:1. D The structure shown is able to conduct electricity. X P X P X P Y Y Y Y Y Y Anglo-Chinese School (Barker Road) Preliminary Examination 2017 Secondary 4 Express Chemistry (5073) Page 5 of 17 8. The diagram shows part of the structure of a salt, XY. Which statement is correct? A Each Y ion is bonded to five X+ ions. B Each X atom is bonded to six Y atoms. C The ratio of X+ to Y is 1 : 1. D The structure shown is able to conduct electricity. 9. Sodium carbonate is added to 1.0 mol/dm3 of excess ethanoic acid, hydrochloric acid and sulfuric acid separately. Which correctly matches the graph to the acid used in each reaction? sulfuric acid hydrochloric acid ethanoic acid A 1 2 4 B 1 4 3 C 2 3 4 D 2 4 3

_______________________________________________________________________________________________________________________________________________________________________________________ Page 3 5 Sodium carbonate is added to separate solutions of excess 1.0mol/dm3 ethanoic acid, hydrochloric acid and sulfuric acid. Which correctly matches the graph to the acid used in each reaction? [ACSB’17] Ethanoic acid Hydrochloric acid Sulfuric acid A 4 2 1 B 3 4 1 C 4 3 2 D 3 4 2 6 Carbon disulfide, CS2 is a simple covalent compound used in the manufacturing of polymers and fibres. A student made the following statements: • CS2 has a low boiling point. • CS2 has good electrical conductivity when molten. • CS2 is very soluble in water. • CS2 is a crystalline solid at room temperature. How many statement(s) is/are correct about CS2? [BBSS’17] A 1 B 2 C 3 D 4 7 Bones contain a complex mixture of calcium salts, proteins and other materials. When a piece of bone is strongly heated in a current air, the only residue is calcium oxide. From a sample of 50.0g of bone, 14.0g of calcium oxide was obtained. What is the percentage by mass of calcium in the bone? [BBSS’17] A 10.0% B 14.0% C 20.0% D 28.0% 8 5.0cm3 of gaseous hydrocarbon reacted with excess oxygen to form 30.0cm3 carbon dioxide and 15.0cm3 water vapour. What is the formula of the hydrocarbon? [BBSS’17] A CH4 B C2H4 C C3H6 D C6H6 Anglo-Chinese School (Barker Road) Preliminary Examination 2017 Secondary 4 Express Chemistry (5073) Page 5 of 17 8. The diagram shows part of the structure of a salt, XY. Which statement is correct? A Each Y ion is bonded to five X+ ions. B Each X atom is bonded to six Y atoms. C The ratio of X+ to Y is 1 : 1. D The structure shown is able to conduct electricity. 9. Sodium carbonate is added to 1.0 mol/dm3 of excess ethanoic acid, hydrochloric acid and sulfuric acid separately. Which correctly matches the graph to the acid used in each reaction? sulfuric acid hydrochloric acid ethanoic acid A 1 2 4 B 1 4 3 C 2 3 4 D 2 4 3

_______________________________________________________________________________________________________________________________________________________________________________________ Page 4 9 An aqueous solution of sulfuric acid has a concentration of 1.0mol/dm3. Different volumes of the acid are added to different volumes of aqueous sodium hydroxide. What is the concentration, in mol/dm3, of the aqueous sodium hydroxide? [BBSS’17] A 0.60 B 0.75 C 1.50 D 3.00 10 The diagram below shows the structural formula of a molecule of hydrazine, N2H4. Which is true of the number of electrons in the molecule? [BDMS’17] Total number of electrons involved in bonding Total number of electrons not involved in bonding A 5 4 B 5 8 C 10 4 D 10 8 11 What does a solution of hydrogen chloride in ethanol contain? [BDMS’17] A Ethanol molecules and hydrogen chloride molecules B Ethanol molecules, hydrogen ions and chloride ions C Ethanol ions and hydrogen chloride molecules D Ethanol ions, hydrogen ions and chloride ions 12 Which sample contains the most number of atoms? [BDMS’17] A 0.5mol of C2H6 B 1.0mol of SO3 C 1.5mol of CO2 D 3.0mol of He BBSS 2017 O Prelim/ Sec 4E/Chem 5073 P1 Applying Past Knowledge to New Situation 6 12 Which volume of 1.0 mol/dm3 hydrochloric acid is required to react completely with 1.25 g of zinc carbonate? A 10 cm3 B 20 cm3 C 100 cm3 D 200 cm3 13 5.0 cm3 of gaseous hydrocarbon reacted with excess oxygen to form 30.0 cm3 of carbon dioxide and 15.0 cm3 of water vapour. What is the formula of the hydrocarbon? A CH4 B C2H4 C C3H6 D C6H6 14 An aqueous solution of sulfuric acid has a concentration of 1.0 mol / dm3 Different volumes of the acid are added to different volumes of aqueous sodium hydroxide. The diagram shows an apparatus used to separate hexane (boiling point, 70oC) and What is the concentration of the aqueous sodium hydroxide? A 0.6 mol / dm3 B 0.75 mol / dm3 C 1.5 mol / dm3 D 3.0 mol / dm3 15 A student writes down four statements about two gases, hydrogen chloride and carbon monoxide. • One mole of each gas has the same mass. • One mole of each gas occupies the same volume at room temperature and pressure. • One mole of each gas has the same number of atoms. • One mole of each gas has the same number of molecules. How many of these statements is/are correct? A 1 B 2 C 3 D 4 volume of H2SO4 /cm3 volume of NaOH / cm3 N H N HH H

_______________________________________________________________________________________________________________________________________________________________________________________ Page 5 13 Which substances can be used to reduce atmospheric pollution caused by flue gases? [BDMS’17] A Ammonium carbonate and ammonium sulfate B Ammonium sulfate and calcium carbonate C Ammonium sulfate and calcium oxide D Calcium carbonate and calcium oxide 14 Which is the correct use of the different fractions in crude oil? [BDMS’17] Fraction Use A Bitumen Lubricating machine parts B Kerosene Fuel for aircraft C Naphtha Pave roads D Petrol Making