CHIJ 4NA Sci (Chem) Prelim 2023_P3

Index Number Class Name CHIJ ST JOSEPH’S CONVENT PRELIMINARY EXAMINATIONS NA SCIENCE (CHEMISTRY) Paper 3 Multiple Choice Secondary 4 Normal (Academic) NA 5105/03 5107/03 Thursday, 27 July 2023 Papers 3 and 4: 1 hour and 15 minutes Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write your name, index number and class on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Paper 3: There are twenty 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 answer sheet. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. You are advised to spend no longer than 30 minutes on Paper 3. You may proceed to answer Paper 4 as soon as you have completed Paper 3. A copy of the Periodic Table is printed on page 8. This document consists of 8 printed pages.

2 Paper 3 (20 marks) Answer all questions. 1 The diagrams below show two methods of collecting gases. Which row gives the properties of a gas which can be collected by both methods? property 1 property 2 A insoluble in water denser than air B insoluble in water less dense than air C soluble in water denser than air D soluble in water less dense than air 2 The table shows the boiling points of some of the elements present in air. element boiling point / °C argon -186 helium -269 neon -246 nitrogen -196 oxygen -183 Which elements are liquid at -200 °C? A argon, helium and neon B argon, nitrogen and oxygen C helium and neon only D nitrogen and oxygen only

3 3 Which observation shows that a liquid is a pure substance? A It boils at a fixed temperature. B It cannot be broken down into any simpler substances. C It conducts electricity at room temperature. D It is colourless. 4 A sample of a white crystalline substance is heated in the absence of oxygen. It melts sharply at 120 °C, but on further heating gives off smoky fumes and a black solid remains. From this information, we can conclude that the white crystalline substance is A a compound which combusted to form two products. B a compound which decomposed to form simpler substances. C a mixture of substances which combined chemically. D an element which decomposed to form simpler substances. 5 A sodium atom is represented as 𝑁𝑎11 23 . How many electrons does one atom of sodium contain? A 11 B 12 C 23 D 34 6 Which row represents an ion? number of protons number of neutrons number of electrons A 1 0 1 B 3 4 3 C 6 6 6 D 11 12 10

4 7 The