HKCE PAST PAPERS 86-94/APPENDIX/PAGE 1
SECTION A
LABORATORY SAFETY (AND MISCELLANEOUS)
1987
39. Which of the following hazard warning labels should be attached to a bottle of liquid bromine?
30.
The above diagram represents the results of a paper chromatography experiment. It can be concluded that the pigments present in mixture M are A. P, R and T. B. P, Q and T. C. P, R and another unknown pigment. D. P and two other unknown pigments. 1988 8.
Large crystals of a salt can be obtained by A. adding ice to a hot, saturated solution of the salt. B. allowing a hot, saturated solution of the salt to stand overnight at room temperature. C. heating a saturated solution of the salt to dryness. D. cooling a hot, saturated solution of the salt under running tap water.
A. B. C. D.
(1) & (2) only (1) & (4) only (1), (3) & (4) only (2), (3) & (4) only
1989 27. Which of the following combinations would cause “striking back” in a Bunsen flame? Air hole Gas supply A. fully closed too weak B. fully closed too strong C. fully open too weak D. fully open too strong
HKCE PAST PAPERS 86-94/APPENDIX/PAGE 2
49. Which of the following experimental procedures should NOT be carried out in the laboratory? A. cutting sodium metal with a knife under paraffin oil B. adding a 1 cm3 piece of potassium metal to a beaker of 2 M hydrochloric acid C. adding concentrated sulphuric acid to copper(II) sulphate crystals in a test tube using a dropper D. mixing bromine water with tetrachloromethane in a boiling tube
1993 41. Which of the following experiments is potentially hazardous and should NOT be carried out on a laboratory bench? A. heating ammonium nitrate strongly in a test tube B. passing ethene through bromine water in a conical flask C. adding a small piece of sodium to a beaker of ethanol D. pouring a small amount of concentrated nitric acid into a trough of water.
1990 42. 44. If dilute hydrochloric acid gets into a student’s eye during an experiment, the first thing the student should do is to A. dial 999 for help. B. wash the eye with water. C. wash the eye with dilute ammonia solution. D. wash the eye with dilute sodium hydroxide solution. 1991 5.
Tetrachloromethane is a common solvent in the chemistry laboratory. Which of the following hazard warning labels should be displayed on a bottle of tetrachloromethane?
A. B. C. D.
(1) only (2) only (1) & (3) only (2) & (3) only
Which of the following solids can be purified using the above set-up? A. potassium iodide B. ammonium chloride C. lead(II) bromide D. sodium hydrogencarbonate
1994
HKCE PAST PAPERS 86-94/APPENDIX/PAGE 3
32. Which of the following label(s) should be placed on a bottle containing tetrachloromethane?
A. B. C. D.
(1) only (2) only (1) & (3) only (2) & (3) only