2022 MSS Chem Prelims P1

2 MONTFORT SECONDARY SCHOOL CHEMISTRY PRELIMS 2022 P1 Answer all questions. Choose the one you consider correct and record your choice with a soft pencil on a separate Answer Sheet. 1 Which piece of apparatus could be used to determine the end-point of the reaction between hydrochloric acid and potassium hydroxide? A electronic balance B gas syringe C stopwatch D thermometer 2 A student sets up the following apparatus to collect a gas. What is the possible identity of the gas and drying agent? gas drying agent A ammonia concentrated sulfuric acid B ammonia calcium oxide C hydrogen chloride calcium oxide D hydrogen chloride concentrated sulfuric acid ���

3 3 A student uses the following experimental set-up to separate mixtures. Which mixture can be separated into its components using this set-up? A ammonium chloride and iodine B copper(II) sulfate and sodium chloride C copper(II) sulfate and sugar D sodium chloride and ammonium chloride 4 Some properties of substances P, Q, R and S are given in the table. substance percentage composition by mass electrical conductivity when solid effect of heat P fixed yes solid burns brightly to form an oxide Q fixed no solid decomposes to form simpler substances R varies no liquid burns to form carbon dioxide and water S varies yes solid melts Which classification of the substances as an element, a mixture or a compound is correct? element mixture compound A P R Q, S B S Q, R P C R S Q, P D P R, S Q ���

4 5 An unknown substance melts at -210 °C and boils at -196 °C. Which row correctly describes the arrangement and movement of the particles of this substance at -204 °C? arrangement movement A closely packed in a disorderly manner sliding past one another B closely packed in a disorderly manner vibrating about fixed positions C closely packed in an orderly manner sliding past one another D closely packed in an orderly manner vibrating about fixed positions 6 A mixture containing an equal volume of two miscible liquids is heated as shown. When the mixture starts boiling and the thermometer first registers a steady reading, at which position, A, B, C, or D, will there be the highest proportion of liquid with the higher boiling point? ���

5 7 Paper chromatography is carried out on three different mixtures of dyes, using the same solvent. Each mixture contains at least one of the dyes W, X, Y and Z. The Rf values of the dyes in the three mixtures are shown. dye Rf values from mixture 1 Rf values from mixture 2 Rf values from mixture 3 W 0.14 0.14 0.14 X 0.00 0.00 0.00 Y 0.50 0.50 0.50 Z 0.82 0.82 0.00 Which conclusion is correct? A Dye W is nearest to the solvent front and is present only in mixture 1 and mixture 3. B Dye X has travelled furthest up the chromatography paper. C Dye Y is the only dye present in all three mixtures. D Dye Z is nearest the solvent front and is found in only two of the mixtures.