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 1111: When iron is exposed to moisture and it rusts, the value of ΔG for the reaction is Options:
  A) neutral
  B) zero
  C) positive
  D) negative
  Show Answer
  The correct answer is D .
• Question 1112:

  

  The graph above demonstrate the effect of

  Options:
  A) surface area on the rate of reaction
  B) catalyst on the rate of reaction
  C) pressure on the rate reaction
  D) concentration on the rate of reaction
  Show Answer
  The correct answer is A .
• Question 1113: Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because Options:
  A) zinx is not rendered passive by acid
  B) hydrogen produced is oxidized to water
  C) oxides of nitrogen are produced
  D) all nitrates are soluble in water
  E) trioxonitrate(v)acid is a strong acid
  Show Answer
  The correct answer is E .
• Question 1114: A catalyst speeds up the rate of chemical reaction by Options:
  A) taking part in the reaction
  B) increasing the activation energy of the reaction
  C) lowering the activation energy of the reaction
  D) increasing the heat content
  Show Answer
  The correct answer is C .
• Question 1115:

  How many bonding pair are present in carbon(iv)oxide?

  Options:
  A) 4
  B) 3
  C) 2
  D) 1
  Show Answer
  The correct answer is A .
• Question 1116: In the laboratory preparation of ethyl ethanoate, the water present in the mixture is removed using a solution of Options:
  A) an hydrous CaCl₄
  B) concentrated NaCO₄
  C) dilute NaOH
  D) concentrated H₄SO₄
  Show Answer
  The correct answer is D .
• Question 1117:

  The refreshing and characteristic taste of soda water and other soft drinks is as a result of the presence of

  Options:
  A) carbon(IV)oxide
  B) carbon(ll)oxide
  C) soda
  D) glucose
  Show Answer
  The correct answer is A .
• Question 1118:

  In the reaction:

  2Hl_(g) ↔ H_2(g) + l_2(g)' ΔH = 10 kj;

  The concentration of iodine in the equilibrium mixture can be increased by?

  Options:
  A) raising the pressure
  B) raising the temperature
  C) adding a catalyst
  D) lowering the pressure
  Show Answer
  The correct answer is B .
• Question 1119: A piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B)when ignited in a crucible produces the oxide of the metal(m). The METAL M is Options:
  A) Zn
  B) Cu
  C) Al
  D) Au
  E) Ca
  Show Answer
  The correct answer is A .
• Question 1120: The processes which return carbon (IV) oxide to the atmosphere include Options:
  A) respiration, decay and combustion
  B) photosynthesis, respiration and transpiration
  C) ozone depletion, combustion and decay
  D) photosynthesis, decay and respiration
  Show Answer
  The correct answer is A .