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 1061: Which of the following samples will react fastest with dilute trioxonitrate (V) acid? Options:
  A) 5 g of lumps of CacO₃ at 25°C
  B) 5 g of powered CacO₃ at 25°
  C) 5 g of lumps of CaCO₃ at 50°C
  D) 5 g of powered CaCO₃ AT 50°C
  Show Answer
  The correct answer is D .
• Question 1062: In the preparation of ammonia, which of the following is used as the drying agent? Options:
  A) CaO
  B) CaCI₂
  C) Conc. H₂SO₄
  D) P₂O₅
  E) H₃PO₄
  Show Answer
  The correct answer is A .
• Question 1063:

  Which of the following is a redox reaction?

  Options:
  A) KCI_(aq) + H₂SO_4(aq) → KHSO_4(aq) + HCI_(aq)
  B) 2FeBr_2(aq) + Br_4(aq) → 2FeBr_3(aq)
  C) 3AgNO_(aq) + FeCl_3(aq) → 3AgCl_(aq) + Fe(NO₃)_3(aq)
  D) H₂CO_3(aq) → H₂O_(I)2- + CO_2(g)
  Show Answer
  The correct answer is B .
• Question 1064: The boiling point of water is higher than that of methanol because? Options:
  A) water is oxide while methanol is an alcohol
  B) inter molecular forces in water are stronger than those in methanol
  C) water is an inorganic compound while methanol is organic
  D) water is an ionic compound while methanol is a covalent compound
  E) water is more reactive than methanol
  Show Answer
  The correct answer is B .
• Question 1065: 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 .
• Question 1066:

  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 1067: A pure solid usually melts? Options:
  A) over a wide range of temperature
  B) over a narrow range of temperature
  C) at a lower temperature than the impure one
  D) at the same temperature as the impure one
  Show Answer
  The correct answer is B .
• Question 1068: The reddish–brown rust on ion roofing sheets consists of Options:
  A) Fe³ + (H₂O)₆
  B) FeO.H₂O
  C) Fe₂O₃.3H₂O
  D) Fe₃O₄.2H2₂O
  Show Answer
  The correct answer is C .
• Question 1069: 60cm³ of hydrogen are sparked with 20cm³ of oxygen at 100°C and 1 atmosphere. The total volume of the residual gases is? Options:
  A) 60 cm³
  B) 10 cm³
  C) 40 cm³
  D) 30 cm³
  E) 70 cm³
  Show Answer
  The correct answer is A .
• Question 1070:

  What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?

  Options:
  A) C${}_4$H${}_8$O${}_4$
  B) CH${}_2$O
  C) C${}_2$H${}_4$O${}_2$
  D) C${}_3$H${}_6$O${}_3$
  Show Answer
  The correct answer is B .