41.An element which exists in more than one crystalline form is said to exhibit
- A. Polymorphism
- B. isotopy
- C. allotropy
- D. isomerism
42.A mixture of starch solution and potassium oxide was placed in a test tube. On adding dilute tetraoxosulphate (VI) acid then K₂Cr₂O₇ solutions, a blue-black colour was produced. In this reaction, the
- A. iodide is oxidized
- B. tetraoxosulphate (VI) acid acts as an oxidizing agent
- C. starch has been oxidized.
- D. K₂CrcO₇ is oxidized.
43.Which of the following statements is true?
- A. The heat of solution of NaOH is positive?
- B. The NaOH gains heat from the surrounding
- C. The heat of solution of NaOH is negative.
- D. The dissolution of NaOH in water is endothermic
44.Which property of a reversible reaction is affected by a catalyst?
- A. Heat content (enthalpy)
- B. energy activation
- C. free energy change
- D. equilibrium position
45.Which of the following is used in fire extinguishers?
- A. Carbon (ii) oxide
- B. carbon (iv) oxide
- C. sulphur (iv) oxide
- D. ammonia
46.When H₂S gas is passed into a solution of iron (iii) chloride, the colour changes from yellow to green. This is because
- A. H₂S is reduced to S
- B. Fe³⁺ ions are oxidized by H₂S
- C. Fe³⁺ ions are oxidized by Fe²⁺ ions
- D. Fe³+ ions are reduced to Fe²⁺ ions.
47.Suitable reagents for the laboratory preparation of nitrogen are ___.
- A. sodium dioxonitrate (III) and ammonium chloride
- B. sodium trioxonitrate (V) and ammonium chloride
- C. sodium chloride and ammonium trioxonitrate (V)
- D. sodium chloride and ammonium diozonitrate
48.The thermal decomposition of copper (II) trioxonitrate (V) yields copper (II) oxide, oxygen and ___
- A. nitrogen (II) oxide
- B. nitrogen (I) oxide
- C. nitrogen (IV) oxide
- D. nitrogen.
49.Which of the following is an example of a chemical change?
- A. freezing of water
- B. dissolution of NaCl
- C. rusting of iron
- D. separation a liquid mixture by distillation.
50.The electronic configuration in the ground state of the chloride ion (Cl⁻) is
- A. 1s² 2s² 2p⁶ 3s² 3p⁵
- B. 1s² 2s² 2p⁶ 3s² 3p⁶
- C. 1s² 2s² 2p⁶ 3s² 3p⁷
- D. 1s² 2s² 2p⁶ 3s² 3p⁷
51.Which of the following is not a member of the homologous series of paraffins (alkanes)?
- A. C₃H₆
- B. C₅H₁₂
- C. C₇H₁₆
- D. C₂₄H₄₈
52.Which of the following statement is an exception in the assumptions of the kinetic theory of gases?
- A. The particles are of negligible size
- B. The particles are in constant random motion
- C. The particles are of negligible mass
- D. The particles collide with each other.
53.An example of alcohol is
- A. CCl₄
- B. CH₃COOH
- C. CHCl₃
- D. CH₃OH
54.Hypochlorous acid is used as a bleach because
- A. It is a strong acid
- B. It yields chlorine readily in pure water
- C. It is an oxidizing agent
- D. It is a weak acid
55.Which of the following compounds will form a solution if exposed to air?
- A. Na₂CO₃.10H₂O
- B. NaNO₃
- C. CuSO₄
- D. CaCl₂
56.Consider the following exothermic reaction 2SO₂(g) + O₂(g) <----> 2SO₃(g) If the temperature of the reaction is reduced from 8000C to 5000C, and no other change takes place, then
- A. the reaction rate increases
- B. concentration of SO₃ decreases
- C. concentration of SO₃ increases
- D. O₃ gas becomes unreactive
57.Alkanoates are formed by the reaction of alkanoic acid with ___.
- A. alkyl halides
- B. alkanols
- C. ethers
- D. sodium
58.Methylethanoate reacts with ammonia to yield __
- A. methylamine and ethanol
- B. ethylamine methanol
- C. methanamide and ethanol
- D. ethanamide and methanol
59.Crude copper can be purified by the electrolysis of CuSO4 if
- A. Platinum electrodes are used
- B. The crude copper is made the anode of the cell
- C. The crude copper is made the cathode of the cell
- D. Crude copper are used.
60.Aluminium is extracted commercially from its ore by
- A. Heating aluminium oxide with coke in a furnace
- B. The electrolysis of fused aluminium oxide in cryolite
- C. Treating cryolite with sodium hydroxide solution under pressure.
- D. Heating sodium aluminium silicate to a high temperature