2023 CGS Chem Prelims P1

Class: Register No: Name: READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluids. Write your name, index number and class on the answer sheet in the spaces provided. 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 OTAS 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 14. The use of an approved scientific calculator is expected, where appropriate. This booklet consists of 14 printed pages, including the cover page. CRESCENT GIRLS’ SCHOOL SECONDARY FOUR PRELIMINARY EXAMINATION 2023 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 6092/01 30 August 2023 1 hour

2 1 Which is the best method to collect a sample of ammonia gas? A bubble the gas into hydrochloric acid and collect with an inverted measuring cylinder B bubble the gas into water and collect with an inverted measuring cylinder C downward delivery D upward delivery 2 The apparatus can be used to show the diffusion of gases. A beaker containing gas P was placed over a porous pot containing gas Q. The resulting water levels in a U-tube are shown below. Which statement is correct? A Gas P has a larger relative molecular mass than gas Q. B Gas P has a smaller relative molecular mass than gas Q. C Gas P has the same relative molecular mass as gas Q. D It is not possible to determine which gas has a larger relative molecular mass. 3 The results of a paper chromatography experiment are shown. X is an aqueous solution of a salt of a coloured transition element. Y is an aqueous solution of a salt of a Group I element. Which row about the spot produced by X and Y is correct? larger Rf value requires use of locating agent A X X B X Y C Y X D Y Y X Y solvent front start line

3 4 Which pair of reagents could be used in a test for sulfate ions in an aqueous solution? A aqueous barium nitrate and nitric acid B aqueous barium nitrate and sulfuric acid C aqueous silver nitrate and hydrochloric acid D aqueous silver nitrate and nitric acid 5 An element Z exists as three isotopes, two of which have isotopic masses of 50 and 52. The diagram shows the mass spectrum of the element Z which shows the relative percentage abundance of two of its isotopes. What is the isotopic mass of the third isotope if the relative atomic mass of element Z is 52.033? A 51 B 53