1) A magnesium ribbon, Mg is put into a test tube containing hydrochloric acid, colourless bubbles were produced. What are the colourless bubbles and how to identify them ? a) Carbon dioxide, CO2 . Pass the gas through limewater. b) Oxygen, O2 . Place a lighted wooden splinter near the mouth of the test tube. c) Hydrogen gas, H2 . Place a moist litmus red paper near the mouth of the test tube.   d) Ammonia gas, NH3 . Pass through the gas into acidified potassium manganate (VII) solution. e) Hydrogen gas, H2 . Place a lighted wooden splinter near the mouth of the test tube containing gas.  2) Bromine water, Br2 was added into both the test tubes. Find the name of the substance contained in each of the test tube. a) Brown - Heptane , Colourless - Heptene b) Brown - Ethanol , Colourless - Butanol c) Brown - Methanoic acid , Colourless - Liquid nitrogen  d) Brown - Hexene , Colourless - Octane e) Brown - Pentane , Colourless - Heptanol 3) Sodium, Lithium and Magnesium. Arrange these according to their reactivity towards oxygen in a descending order. a) Sodium, Na - Magnesium, Mg - Lithium, Li b) Lithium, Li - Sodium, Na - Magnesium, Mg c) Magnesium, Mg - Sodium, Na - Lithium, Li d) Lithium, Li - Magnesium, Mg - Sodium, Na e) Magnesium, Mg - Lithium, Li - Sodium, Na 4) Which of the following statement is correct about covalent and ionic bond ? a) Both can conduct electricity in all state of matter. b) Ionic bond can dissolve in water, but covalent bond can't. c) Covalent bond has high melting / boiling, whereas ionic bond has low boiling / melting point. d) Both have charged particles. e) Both can dissolve in organic solvent. 5) KOH + NH4 Cl = ? Complete the reaction. a) KOH + NH4 Cl = KCl + H2 O + NH3 b) KOH + NH4 Cl = KCl + NH4 OH c) 2KOH + 2NH4 Cl = 2KCl + 2NH5 + O2 6) 10 mol of solid zinc chloride, ZnCl2 dissolved in water to produce 5dm3 of solution.  a) 0.5 mol/dm3 b) 1.25 mol/dm3 c) 1.0 mol/dm3 d) 2.0 mol/dm3 e) 1.5 mol/dm3 7) 0.1 mol of solid calcium chloride, CaCl2 is dissolved in 500cm3 of distilled water. Find the molarity. a) 0.0002 mol/dm3 b) 1.0 mol/dm3 c) 0.2 mol/dm3 d) 2.0 mol/dm3 e) 0.5 mol/dm3 8) A beaker contains 200 cm3 of 0.2 mol/dm3 lead (II) nitrate, Pb(NO3 )2 . How many moles of lead (II) nitrate, Pb(NO3 )2 is in the beaker ?  a) 1 mol b) 0.02 mol  c) 40 mol d) 0.002 mol e) 0.04 mol 9) 75 cm3 of 2.0 mol/dm3 nitric acid, HNO3 that is diluted to x mol/dm3 when 25cm3 distilled water is added. Calculate the value of x. a) 1.5 b) 2.0 c) 0.5 d) 3.0 e) 150 10) Determine the volume of 2.0 mol/dm3 hydrochloric acid, HCl needed to be pipetted into a volumetric flask 250cm3 to produce 0.2 mol/dm3 of HCl, in dm3 .  a) 0.01 b) 25 c) 0.025 d) 0.005 e) 0.02

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