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 961: The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its Options:
  A) electrovalency
  B) electron affinity
  C) electropositivity
  D) electronegativity
  Show Answer
  The correct answer is D .
• Question 962: The colour changes observed when testing for reducing agents using acidified potassium heptaoxodichromate (IV) solution is Options:
  A) yellow to purple
  B) orange to green
  C) green to orange
  D) purple to yellow
  Show Answer
  The correct answer is B .
• Question 963:

  32g of anhydrous copper(ii)tetraoxosulphate(vi) dissolved in 1dm${}^3$ of water generated 13.0kj of heat. The heat solution is?

  Options:
  A) 26.0kj/mol
  B) 65.0kj/mol
  C) 130.0kj/mol
  D) 260.0kj/mol
  Show Answer
  The correct answer is B .
• Question 964:

  SO${}_2$ + O${}_2$ 2SO${}_3$

  In the reaction above, the most suitable catalyst is?

  Options:
  A) chromium(vi)oxide
  B) iron(iii)oxide
  C) copper(i)oxide
  D) vanadium(v)oxide
  Show Answer
  The correct answer is D .
• Question 965: If an equilibrium reaction has ΔH > 0, the reaction will proceed favourably in the forward direction at Options:
  A) High temperature
  B) Any temperature
  C) Low temperature
  D) Minimum temperature
  Show Answer
  The correct answer is A .
• Question 966: 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 967: Brass and bronze are both metallic alloys. Which of the following constituents is common to both alloys? Options:
  A) Tin
  B) Zinc
  C) Copper
  D) Lead
  E) Aluminium
  Show Answer
  The correct answer is C .
• Question 968: A sample of orange juice is found to have a pH of 3.80. What is he concentration of the hydroxide ion in the juice? Options:
  A) 1.6 x 10^-4
  B) 6.3 x 10^-11
  C) 6.3 x 10^-4
  D) 1.6 x 10^-11
  Show Answer
  The correct answer is B .
• Question 969: If y is an oxidizing agent that reacts with a reducing agent, Z, which of the following is correct? Options:
  A) Y increases in oxidation number
  B) Y becomes reduced
  C) Z loses protons
  D) Z gains protons
  Show Answer
  The correct answer is B .
• Question 970: In which of the following are water molecules in the most disorderly arrangement? Options:
  A) Ice at -10°C
  B) Ice at 0°C
  C) Water at 100°C
  D) Steam at 100°C
  Show Answer
  The correct answer is D .