2017 MGS Prelim P1

Page 2 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 1 The apparatus shows the diffusion of 3 gases. Two beakers containing gas R were placed over two porous pots containing gases P and Q as shown. What is the relative molecular masses of gases P, Q and R in ascending order? Lowest Highest A Q P R B Q R P C P R Q D P Q R 2 An impure sample of gas Y contains some water vapour and an impurity that is soluble in water. Gas Y is insoluble in water and less dense than air. Which of the following is the correct order for the apparatus to be joined together to collect a pure, dry sample of gas Y? A 1, 4, 2 B 1, 4, 3 C 4, 1, 2 D 4, 1, 3 1 drying agent water 4 2 3 water R P R Q water porous pot porous pot

Page 3 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 3 Ethanol and butanol have boiling point s of 78 C and 118 C respectively. The apparatus shown is used to distil ethanol from a mixture of ethanol and butanol. Which graph shows the change in the concentration of ethanol in flask F as the distillation proceeds? A B C D 4 The chromatogram of a sweet is shown in the diagram. Which of the following statements can be deduced from the chromatogram? A The sweet is blue in colour. B The red dye is more soluble than the blue dye. C The molecules of the blue dye are heavier than that of the red dye. D The Rf value of the blue dye is greater than that of the red dye. mixture of ethanol and butanol red blue start line solvent front flask F

Page 4 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 5 The models and formulae for two molecules are shown. Which is the correct model for a molecule of the compound formed between X and Z? A B C D 6 Element X is found in the Periodic Table with atomic number p. It forms an ionic oxide, X2O. Element Y has atomic number p+3. What is the formula of the oxide of Y? A YO B YO2 C Y2O D Y2O3 7 The formation of metallic chlorides involves the transfer of electrons from a metal atom to chlorine atoms. In the formation of one mole of which metallic chloride do the metal atoms not transfer exactly two moles of electrons? A barium chloride B iron (II) chloride C magnesium chloride D sodium chloride

Page 5 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 8 The table shows information about particles R and S. Particle Number of protons neutrons electrons R 11 12 10 S 19 20 18 Which of the following statement is correct for both R and S? A Both are atoms in the same Group. B Both are isotopes of the same element. C Both are positive ions in the same Gr