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:

  A given amount of gas occupies 10.0dm5 at 4atm and 273°C. The number of moles of the gas present is [Molar volume of gas at s.t.p = 22.4dm${}^3$]

  Options:
  A) 0.89 mol
  B) 1.90 mol
  C) 3.80 mol
  D) 5.70 mol
  Show Answer
  The correct answer is A .
• Question 822:

  When a substance is oxidized, it

  Options:
  A) Loses electrons
  B) Gains oxygen atoms
  C) Gains electrons
  D) Loses protons (H+ ions)
  Show Answer
  The correct answer is A .
• Question 823: Sodium hydrogen should be stored in properly closed containers because it? Options:
  A) readily asborbs water vapour to air
  B) is easily oxidize by atmospheric oxygen
  C) turns golden yellow when exposed to light
  D) melts at a low temperature
  Show Answer
  The correct answer is A .
• Question 824: Calculate the quantity of electricity in coulombs required to liberate 10g of copper from a copper compound[Cu=64, F = 96500 Cmol^-1] Options:
  A) 32395.5
  B) 30156.3
  C) 60784.5
  D) 15196.5
  Show Answer
  The correct answer is B .
• Question 825: When at equilibrium, which of the reactions below will shift to the right if the pressure is increased and the temperature is kept constant? Options:
  A) 2SO_3(g) ↔ 2SO_2(g) + O_2(g)
  B) 2CO_2(g) ↔ 2CO_(g) + O_2(g)
  C) 2H_2(g) + O_2(g) ↔ 2H₂O_(g)
  D) 2NO_(g) ↔ N_2(g) + O_2(g)
  Show Answer
  The correct answer is C .
• Question 826:

  How many neutrons are present in atom with mass number and atomic number 37 and 17 respectively?

  Options:
  A) 18
  B) 20
  C) 37
  D) 17
  Show Answer
  The correct answer is B .
• Question 827: In the industrial production of H₂ is removed by (solution) Options:
  A) washing under pressure
  B) drying over phosphorus (V) oxide
  C) passing the mixture to the limewater
  D) using ammonical copper (I) chlorine
  Show Answer
  The correct answer is A .
• Question 828:

  

  Which of the structural forms above is ethanoic acid is

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is E .
• Question 829:

  Which transition metal is known for its multiple colorful oxidation states and compounds used in pigments and paints?

  Options:
  A) Silver (Ag)
  B) Copper (Cu)
  C) Gold (Au)
  D) Zinc (Zn)
  Show Answer
  The correct answer is B .
• Question 830: A suitable solvent for iodine and nephthalene is Options:
  A) carbon (IV) sulphide
  B) ethanol
  C) water
  D) benzene
  Show Answer
  The correct answer is B .