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 1791: Alkanols have the general molecular formula Options:
  A) C₁H_2n-2
  B) C₁H_2n-1CHO
  C) C₁H_2n-2OH
  D) C₂H_2n+1OH
  Show Answer
  The correct answer is D .
• Question 1792: Which of the following compounds would give lilac flame coloration and a white precipitate with acidified barium chloride solution? Options:
  A) KCI
  B) NaNO₃
  C) K₂SO₄
  D) CaSO₄
  Show Answer
  The correct answer is C .
• Question 1793:

  Zn + H₂ SO₄ → ZnSO₄ + H₂

  In the above reaction how much Zinc will be left of 1.0 M of H₂SO?

  [Zn =65, s = 32, O = 16, H = 1]

  Options:
  A) 1.35g
  B) 1.00g
  C) 0.70g
  D) 0.65g
  E) 0.00g
  Show Answer
  The correct answer is A .
• Question 1794: Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution? Options:
  A) Cu²⁺ + 2e^- → Cu(s)
  B) 2Cl^- -2e → Cl₂
  C) Cu_(s) -2e → Cu²⁺_(aq)
  D) Cu²⁺_(aq) + 2Cl^-_(aq) → CuCl_2(aq)
  Show Answer
  The correct answer is A .
• Question 1795: A liquid that will dissolve fat is Options:
  A) Hydrochloric acid
  B) Calcium hydroxide
  C) Kerosene
  D) Water
  Show Answer
  The correct answer is B .
• Question 1796:

  5cm³ of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C?

  (Na = 23, Cl = 35.5)

  Options:
  A) 5.00 mole dm³
  B) 5.67 mole dm³
  C) 6.00 mole dm³
  D) 6.67 mole dm³
  E) 7.00 mole dm³
  Show Answer
  The correct answer is D .
• Question 1797:

  What is the PH of 0.00 1 moldm${}^3$ solution of the sodium hydroxide

  Options:
  A) 14
  B) 13
  C) 12
  D) 11
  Show Answer
  The correct answer is D .
• Question 1798: A hydrogen atom which has lost an electron contains Options:
  A) one proton only
  B) one neutron only
  C) one proton and one neutron
  D) one proton, one electronic and one neutron
  Show Answer
  The correct answer is A .
• Question 1799: In which of the following reactions has the oxidation number of nitrogen increased? Options:
  A) 2NO_(g) + Br_2(l) → 2NOBr_(l)
  B) 2NO_(g) + O_2(g) → 2NO_2(g)
  C) FeSO_4(aq) + NO_(g) → Fe(NO)SO_4(s)
  D) 2NO(g) + Cl_2(g) → 2NOCl(l)
  Show Answer
  The correct answer is B .
• Question 1800: Detergents are more advantageous than soaps in hard water districts because Options:
  A) on treatment with hard water they either form soluble calcium salts or do not react with calcium ion
  B) on treatment with hard water they form soluble calcium salts
  C) on treatment with hard water they form sodium salts
  D) on treatment with hard water they are converted into soaps
  E) on treatment with hard water they form more lather than soaps does
  Show Answer
  The correct answer is A .