CGSS 2023 Chemistry Prelim Paper 1

CEDAR GIRLS’ SECONDARY SCHOOL Preliminary Examination 2023 Secondary Four CHEMISTRY 6092/01 Paper 1 Multiple Choice 13 Sep 2023 1 hour Additional Materials: Multiple Choice Answer Sheet 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 Answer Sheet in the spaces provided unless this has been done for you. 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 18. The use of an approved scientific calculator is expected, where appropriate. This document consists of 18 printed pages. [Turn over

2 1 Diagram 1 shows the paper chromatogram of substance X. Diagram 2 shows the cooling curve for substance Y. Which statement about X and Y is correct? A X is a mixture and Y is a pure substance. B X is a pure substance and Y is a mixture. C X and Y are mixtures. D X and Y are pure substances.

3 [Turn over 2 A drop of liquid bromine is placed in the bottom of a gas jar. Brown fumes of bromine vapour slowly spread through the covered gas jar. Why does this happen? A Bromine vapour is less dense than air. B Bromine molecules and the molecules in air are always moving around. C Bromine molecules are smaller than the molecules in air. D Bromine molecules move faster than the molecules in air. 3 Aqueous silver nitrate is added to aqueous barium iodide until no more precipitate forms. The precipitate is filtered off. Dilute sulfuric acid is added to the filtrate until no more precipitate is formed. The precipitate is filtered off. Which statement is correct? A Both precipitates are soluble in excess aqueous sodium hydroxide. B Both precipitates are white. C Effervescence is observed in the second experiment. D Nitric acid is present in the filtrate after the second experiment.

4 4 Which graph shows the number of electrons in the outer shell of an atom, plotted against the proton number for the first ten elements in the Periodic Table? A B C D 5 Element X reacts with nitrogen to form an ionic compound, X3N2. Which formula for compounds formed by X is correct? A XO2 B XS2 C XF2 D X2O 6 Which compound has both ionic and covalent bonds? A ammonium chloride B carbon dioxide C ethyl ethanoate D sodium sulfide

5 [Turn over 7 When a covalent liquid boils, its mole