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 1761:

  A solution X on mixing with AgNO₃ solution, gives a white precipitate solution in NH₃. A Solution Y, when added to X, also gives a white precipiate which is soluble on boiling. Solution Y contains?

  Options:
  A) Ag⁺ ion
  B) Pb²⁺ ion
  C) Pb⁴⁺ ion
  D) Zn²⁺ ion
  E) Al³⁺ ion
  Show Answer
  The correct answer is B .
• Question 1762:

  Zn + 2HCL ZnCl${}_2$ + H${}_2$

  What happens to zinc in the above reaction?

  Options:
  A) oxidized
  B) a reactant
  C) reduced
  D) a metal
  Show Answer
  The correct answer is A .
• Question 1763: Alkanals can be distinguished from alkanones by the reaction with Options:
  A) sudan lll stain
  B) starch iodide paper
  C) lithium tetrahydrido aluminate (lll)
  D) fehling's solution
  Show Answer
  The correct answer is D .
• Question 1764:

  Deliquescent substances are also?

  Options:
  A) efflorescent
  B) anhydrous
  C) hygroscopic
  D) insoluble
  Show Answer
  The correct answer is C .
• Question 1765: The reaction of an alkanol with an alkanoic acid in the presence of concentrated H₂SO₄ will produce an? Options:
  A) alkanal
  B) alkanoate
  C) alkanone
  D) alkyne
  Show Answer
  The correct answer is B .
• Question 1766:

  The number of grammes of potassium hydroxide in 250cm³ of one molar solution is?

  (K = 39, O = 16, H = 1)

  Options:
  A) 40g
  B) 52g
  C) 100g
  D) 26g
  E) 14g
  Show Answer
  The correct answer is E .
• Question 1767: Which of the following electron configurations indicates an atom with the highest ionization energy? Options:
  A) 2,8,7
  B) 2,8,8,1
  C) 2,8,8,2
  D) 2,8,8,7
  Show Answer
  The correct answer is A .
• Question 1768:

  N${}_2$O${}_4$⇔ 2NO${}_2$ ( = -ve)

  From the reaction above, which of these conditions would produce the highest equilibrium yield forN${}_2$O${}_4$?

  Options:
  A) Low temperature and high pressure
  B) Low temperature and low pressure
  C) high temperature and low pressure
  D) high temperature and high pressure
  Show Answer
  The correct answer is A .
• Question 1769: Which of the following substances is the most abundant in the universe? Options:
  A) Carbon
  B) Air
  C) Water
  D) Oxygen
  E) Hydrogen
  Show Answer
  The correct answer is E .
• Question 1770: Carbon (II) oxide is considered dangerous if inhaled mainly because it Options:
  A) can cause injury to the nervous system
  B) competes with oxygen in the blood
  C) competes with carbon (IV) oxide in the blood
  D) can cause lung cancer
  Show Answer
  The correct answer is B .