Chemistry 2019 Past Questions | WAEC

Study the following Chemistry past questions and answers for JAMBWAEC  NECO and Post-JAMB. Get prepared with official past questions and answers for upcoming examinations.

31.  If a catalyst is added to a system, the temperature and the pressure remain constant, there would be no effect on the? 

  • A. activation energy of the reaction
  • B. rate of the reaction
  • C. rate of the reverse reaction
  • D. heat of reaction

32.  consider the following reaction equation: 2NH3 + 3Cl2→ N2 + 6HCl. 

NH3 is acting as?

  • A. a reducing agent
  • B. a dehydrating agent
  • C. a drying agent
  • D. an oxidizing agent

33. The oxidation of chromium in Cr22O7/−27)\(−2?

  • A. +4
  • B. +5
  • C. +6
  • D. +7

34. The process by which alkanoic acid reacts reversibly with alkanols is known as?

  • A. saponification
  • B. esterification
  • C. carboxylation
  • D. halogenation

35.  If the oxidation potential of Mg and Al are +2.37 volts and + 1.66 volts respectively, then the Mg would?

  • A. not replace Al
  • B. be replaced by Al
  • C. remain in the solution
  • D. replace Al

36. consider the reaction represented by the following equation: 2SO2+ O2 2SO3

A decrease in the pressure of the reaction would

  • A. decrease in the concentration of SO2
  • B. have no effect on the reaction
  • C. shift the equilibrium position to the left
  • D. shift the equilibrium position to the right

37. In a mixture of gases which do not react chemically together, the pressure of the individual gas is?

  • A. atmospheric pressure
  • B. vapor pressure
  • C. total pressure
  • D. partial pressure

38. Biotechnology is applied in the? 

  • A. treatment of sewage
  • B. treatment of water
  • C. purification of chemicals
  • D. purification of metals

39. which of the following organic compounds has the lowest boiling point?

  • A. C6H14
  • B. C5H12
  • C. C4H10
  • D. ( CH3 )3

40. Consider the following reaction represented by the following equation: C2H2H2→H2X  H2→H2)X and Y respectively are?

  • A. ethane and ethene
  • B. ethene and ethane
  • C. ethyne and ethene
  • D. ethane and ethyne

41. Which of the following substances can be classified as heavy chemicals?  

  • A. CaOCl2
  • B. H2SO4
  • C. AgNO3
  • D. CaO

42. in Boyle’s law?

  • A. T is constant, P varies directly with V
  • B. P is constant, V varies inversely with T
  • C. V is constant, P varies directly with T
  • D. T is constant, V varies inversely with P

43.  Which of the following apparatus is NOT used in volumetric analysis?

  • A. Pipette
  • B. Burette
  • C. Desiccator
  • D. conical flask

44.  One of the deductions from Rutherford’s alpha particle scattering experiment is that?

  • A. electrons are negatively charged
  • B. electrons have a negligible mass
  • C. nuclei of atoms are positively charged
  • D. protons are positively charged

45. The atoms of 64/29 CU and 65/30Zn have the same number of?

  • A. nucleon
  • B. electrons
  • C. neutrons
  • D. protons

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