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 1221: A certain liquid has a high boiling point. It is viscous, non-toxic, miscible with water being very hygroscopic. This liquid is most likely to be? Options:
  A) CH₃CH₂CH₂HO
  B) CH₃CHOHCH₃
  C) CH₃CH₂CHOHCH₃
  D) CH₂OHCHOHCH₂OH
  Show Answer
  The correct answer is D .
• Question 1222: Which of the following noble gases is commonly found in the atmosphere? Options:
  A) Xenon
  B) Neon
  C) Helium
  D) Argon
  Show Answer
  The correct answer is D .
• Question 1223:

  

  How many more isomers of the compound above can be obtained ?

  Options:
  A) 5
  B) 4
  C) 3
  D) 2
  Show Answer
  The correct answer is B .
• Question 1224:

  The equilibrium reaction between copper (l) chloride and chlorine at 25^oC and 1 atmosphere is represented by the equation:

  2CuCl +Cl₂ ⇌ 2 CuCl₂ ∆H = - 166 KJ. Which of the following statements is TRUE for the reaction, pressure remaining constant?

  Options:
  A) more CuCl is formed at 40^oC
  B) more CuCl₂ is formed at 10^oC
  C) Less CuCl₂ is formed at 10^oC
  D) there is no change in the amount of CuCl₂ formed at 40^oC and10^oC
  E) more CuCl is consumed at 40^oC
  Show Answer
  The correct answer is B .
• Question 1225: When marble is heated to about 1473 K, another white solid is obtained which reacts vigorously with water to give an alkaline solution. The solution contains? Options:
  A) NaOH
  B) KOH
  C) Mg(OH)₂
  D) Zn(OH)₂
  E) Ca(OH)₂
  Show Answer
  The correct answer is E .
• Question 1226: In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because Options:
  A) it makes bauxite a better conductor of electricity
  B) it makes bauxite melt at a lower temperature
  C) it makes aluminium purer
  D) it prevents aluminium from getting oxidized
  E) it protects the carbon electrodes used in the process
  Show Answer
  The correct answer is B .
• Question 1227: An example of oxidation - reduction enzyme is Options:
  A) amylase
  B) protease
  C) lipase
  D) dehydrogenase
  Show Answer
  The correct answer is D .
• Question 1228: What is the pH of 0.001 mol dm^-3 solution of sodium hydroxide Options:
  A) 14
  B) 13
  C) 12
  D) 11
  Show Answer
  The correct answer is D .
• Question 1229: A polymerization reaction is one in which? Options:
  A) small molecules form giant molecules
  B) atoms form molecules
  C) giant molecules form small molecules
  D) molecules form volatile compounds
  E) a molecule rearranges itself
  Show Answer
  The correct answer is A .
• Question 1230:

  The volume occupied by 1.58g of a gas at S.T.P is 500cm${}^3$. What is the relative molecular mass of the gas?  [ G.M.V at S.T.P = 22.4dm${}^3$ ]

  Options:
  A) 28
  B) 32
  C) 44
  D) 71
  Show Answer
  The correct answer is D .