Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 821: Which of the following is a neutralization reaction? Options:
  A) Addition of sodium chloride solution to potassium chloride solution
  B) Addition of trioxonitrate (V) acid (nitric acid) to distilled water
  C) Addition of trioxonitrate (V) acid (nitric acid) to tetraoxosulphate (IV) acid (sulphuric acid)
  D) Addition of trioxonitrate (V) acid (nitric acid) to potassium trioxonitrate (V) (potassium nitrate) solution
  E) Addition of trioxonitrate (V) acid (nitric acid) to potassium hydroxide solution
  Show Answer
  The correct answer is E .
• Question 822:

  Which of the following gases can best be used for demonstrating the fountain experiment?

  (iv) Hydrogen chloride.

  Options:
  A) ii and iii
  B) i and iii
  C) ii and iv
  D) ii only
  E) Nitrogen (ii) Ammonia (iii) Nitrogen (I) oxide
  Show Answer
  The correct answer is C .
• Question 823: The gas responsible for most of the fatal explosions in coal mines is Options:
  A) butane
  B) ethene
  C) ethane
  D) methane
  Show Answer
  The correct answer is D .
• Question 824: the elements that belong to the third period of the periodic table are Options:
  A) Li, Be, Al and P
  B) Na, P, O and Cl
  C) B, C, N and O
  D) Nz, Mg, S and Ar
  Show Answer
  The correct answer is D .
• Question 825: A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that? Options:
  A) collisions are perfectly elastic
  B) forces of repulsion exist
  C) forces of repulsion are in equilibrium
  D) collision are inelastic
  Show Answer
  The correct answer is A .
• Question 826:

  An organic compound with a vapour density 56.5 has the following percentage composition:C =53.1% N = 12.4%, O = 28.3%, H = 6.2%. The molecular formula of the compound is

  Relative atomic masses: N = 14, O = 16, C = 12, H = 1 )

  Options:
  A) C₃H₆O₂N
  B) C₅H₆O₂N
  C) (C₅H₇O₂N)_1/2
  D) C₅H₇O₂N
  E) (C₅H₇O₂N)₂
  Show Answer
  The correct answer is D .
• Question 827:

  Which of the following is an example of an endothermic reaction?

  Options:
  A) Combustion of propane (C${}_3$H${}_8$) to produce carbon dioxide (CO${}_2$) and water (H${}_2$O).
  B) Burning of methane (CH${}_4$) in the presence of oxygen
  C) Formation of table salt (NaCl) from sodium (Na) and chlorine (Cl${}_2$).
  D) Decomposition of hydrogen peroxide (H${}_2$O${}_2$) into water (H${}_2$O) and oxygen (O${}_2$).
  Show Answer
  The correct answer is D .
• Question 828: Metalliods are also referred to as Options:
  A) semi-metals
  B) metals
  C) colliods
  D) non-metals
  Show Answer
  The correct answer is A .
• Question 829: Copper is displaced from the solution of its salts by most metals because it Options:
  A) is a transition element
  B) is at the bottom of the activity series
  C) is very reactive
  D) has completely filled 3d-orbitals
  Show Answer
  The correct answer is B .
• Question 830:

  What mass of Cu would be produced by the cathodic reduction of Cu${}^{2+}$  when 1.60A of current passes through a solution of CuSO${}_4$ for 1 hour. (F=96500Cmol${}^{-1}$ , Cu=64)

  Options:
  A) 7.64g
  B) 3.82g
  C) 1.91g
  D) 0.96g
  Show Answer
  The correct answer is C .