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 1411: Helium is often used in observation balloons because it is? Options:
  A) light and combustible
  B) light and non-combustible
  C) heavy and combustible
  D) heavy and non-combustible
  Show Answer
  The correct answer is B .
• Question 1412: Which of the following will produce a solution with pH less than 7 at equivalent point? Options:
  A) HNO ₃ +NaOH
  B) H ₂SO ₄ + KOH
  C) HC +Mg (OH) ₂
  D) HNO ₃ + KOH
  Show Answer
  The correct answer is C .
• Question 1413: Which of the following hydrogen halides the highest entropy value? Options:
  A) HF
  B) HCl
  C) HBr
  D) HI
  Show Answer
  The correct answer is A .
• Question 1414:

  

  The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

  Options:
  A) spontaneous
  B) isothermal
  C) adiabatic
  D) exothermic
  E) endothermic
  Show Answer
  The correct answer is D .
• Question 1415: Ethanoic acid is Options:
  A) tribasic
  B) unionizeable
  C) monobasic
  D) dibasic
  Show Answer
  The correct answer is C .
• Question 1416: If one of the following oxides is heated with hydrogen or carbon using a bunsen burner, it is not reduced to the metal. Which one is it? Options:
  A) Lead oxide
  B) Magnesium oxide
  C) Copper oxide
  D) Tin oxide
  E) Iron oxide
  Show Answer
  The correct answer is B .
• Question 1417: A few drops of concentrated HNO₃ is added to an unknown solution and boiled for a while. If this produces a brown solution, the cation presents is likely to be Options:
  A) Pb²⁺
  B) Cu²⁺
  C) Fe³⁺
  D) Fe²⁺
  Show Answer
  The correct answer is D .
• Question 1418: Two equal bulbs, one containing ammonia and the other one opened mouth-to mouth to each other at temperature the entropy in the mixture of gases is likely to Options:
  A) remain unchanged
  B) increase
  C) decrease
  D) charge
  Show Answer
  The correct answer is A .
• Question 1419: The forces holding naphthalene crystals together can be overcome when naphthalene is heated to a temperature of 354K resulting in the crystal to melting. These forces are known as? Options:
  A) coulombic
  B) ionic
  C) covalent
  D) Van der waals
  Show Answer
  The correct answer is D .
• Question 1420: The fraction of crude oil used as jet fuel is? Options:
  A) refinery gas
  B) diesel oil
  C) kerosene
  D) gasoline
  Show Answer
  The correct answer is C .