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 581: A hydrocarbon X with a molar mass of 26 consists of 92.3% carbon. What is its molecular formular Options:
  A) C₂H₂
  B) C₃H₃
  C) C₄H₄
  D) C₅H₅
  Show Answer
  The correct answer is A .
• Question 582:

  

  In the diagram above. X is

  Options:
  A) SO₃
  B) SO₂
  C) S
  D) H₂S
  Show Answer
  The correct answer is B .
• Question 583:

  A colored gas that is known to be poisonous and can readily damage the mucous liningof the lungs is?

  Options:
  A) hydrogen sulphide
  B) carbon(ii)oxide
  C) chlorine
  D) sulphur(iv)oxide
  Show Answer
  The correct answer is C .
• Question 584:

  In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

  Options:
  A) 5cm${}^3$
  B) 10cm${}^3$
  C) 20cm${}^3$
  D) 50cm${}^3$
  Show Answer
  The correct answer is D .
• Question 585:

  NH₄Cl_(s) ↔ NH_3(g) + HCL_(g)

  The reaction above can only attain equilibrium if

  Options:
  A) a gaseous reactant is added
  B) one of the products is removed
  C) it is in a closed system
  D) it is an open system
  Show Answer
  The correct answer is C .
• Question 586: The idea of planetary electron was that of Options:
  A) Rutherford
  B) Thompson
  C) Bohr
  D) Dalton
  Show Answer
  The correct answer is A .
• Question 587: If the silver mirror test is positive, it indicates the presence of an Options:
  A) alkyne
  B) alkanol
  C) alkanone
  D) alkanal
  Show Answer
  The correct answer is D .
• Question 588: 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 589: In the extraction of iron, the waste gas from the furnace is a mixture of Options:
  A) PH₃ CO and CO₂
  B) CO and C
  C) N₂ CO and CO₂
  D) PH₃ and CO
  Show Answer
  The correct answer is A .
• Question 590:

  

  In the electrolysis of aqueous solution of K₂SO ₄ in the above cell, which species migrate to the anode?

  Options:
  A) SO^2-OH ^-
  B) K ⁺ and SO ₄^2-
  C) OH and HO
  D) H₃O ⁺ and K
  Show Answer
  The correct answer is A .