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 511: Which of these require crystallization most? Options:
  A) Drug making
  B) Cement making
  C) Paint making
  D) Perfume making
  Show Answer
  The correct answer is A .
• Question 512: A compound that will NOT produce oxygen on heating is? Options:
  A) potasium dioxonitrate (III)
  B) lead (IV) oxide
  C) potassium trioxochlorate (V)
  D) potassium trioxonitrate (V)
  Show Answer
  The correct answer is A .
• Question 513:

  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 514:

  220g of carbon dioxide contains ----- moles

  Options:
  A) 5
  B) 6
  C) 3
  D) 4
  Show Answer
  The correct answer is A .
• Question 515:

  An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

  Reaction of X with yeast forms the basis of the

  Options:
  A) plastic industry
  B) textile industry
  C) brewing industry
  D) soap industry
  E) dyeing industry
  Show Answer
  The correct answer is C .
• Question 516: Three drops of a 1.0 mol dm^-3 solution of NaOH are added to 20 cm³ of a solution of pH 8.4. The pH of the resulting solution will be Options:
  A) Close to that of pure water
  B) Unaltered
  C) Greater than 8.4
  D) Less than 8.4
  Show Answer
  The correct answer is C .
• Question 517: The method that can be used to convert hard water to soft water is Options:
  A) chlorination
  B) passage over activated charcoal
  C) the use of an ion-exchange resin
  D) aeration
  Show Answer
  The correct answer is C .
• Question 518:

  The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?

  Options:
  A) with cool running water
  B) sodium hydroxide solution
  C) iodine solution
  D) sodium trioxonitrate(v) solution
  Show Answer
  The correct answer is A .
• Question 519: What volume of 0.5 MH₂SO₄ will exactly neutralize 20cm³ of 0.1 MNaOH Solution? Options:
  A) 2.0cm³
  B) 5.0cm³
  C) 6.8cm³
  D) 8.3cm³
  Show Answer
  The correct answer is A .
• Question 520: What is the volume of energy required to burn 45cm3 of mixture at S.T.P Options:
  A) 135.0cm³
  B) 150.0cm³
  C) 45.0cm³
  D) 90.0cm³
  Show Answer
  The correct answer is D .