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 1471: Which of the following compounds is used as a gaseous fuel? Options:
  A) CH₃ -CH₂ -CHO₂ -COOH
  B) CH₃ -C = CH
  C) CH₃ -CH₂ -CH₂ -CH₃
  D) CH₂ -CH₂ -CH₃
  Show Answer
  The correct answer is C .
• Question 1472: An isotope has an atomic number of 15 and a mass number of 31. The number of proton it contains is Options:
  A) 16
  B) 15
  C) 31
  D) 46
  Show Answer
  The correct answer is B .
• Question 1473: A fixed mass of gas a volume of 92cm³ at 3°C. When will be its volume at 18C if the pressure remains constant? Options:
  A) 15.3cm³
  B) 87.3cm³
  C) 2.0cm³
  D) 97.0cm³
  Show Answer
  The correct answer is D .
• Question 1474: What is the correct IUPAC name for NO₂^-? Options:
  A) Dioxonitrate (IV) ion
  B) Trioxonitrate (III) ion
  C) Trioxonitrate (IV) ion
  D) Dioxonitrate (II) ion
  Show Answer
  The correct answer is D .
• Question 1475:

  SO${}_3$ is not directly dissolved in water in the industrial preparation of H${}_2$SO${}_4$ by the contact process because

  Options:
  A) SO${}_3$ is an acidic gas
  B) Acid is usually added to water and not water to acid
  C) The reaction between SO${}_3$ and water is violently exothermic
  D) SO${}_3$ does not dissolve readily in water
  Show Answer
  The correct answer is C .
• Question 1476: A sample of temporary hard water can be prepared in the laboratory by? Options:
  A) disolving calcium chloride in distilled water
  B) saturating lime water with carbon (IV) oxide
  C) saturating distilled water with calcium hydroxide
  D) dissolving sodium hydrogen trioxocarbonate (IV) in some distilled water
  Show Answer
  The correct answer is B .
• Question 1477: The atomic radius of Li, Na and K are 1: 33A, 1. 54A and 1. 96A res pectively. Which of the following explaqins this gradation in atomic radius? Options:
  A) electropositivity decreases from Li to Na to K
  B) electronegativity decreases from Li to Na to K
  C) the number of the electron shells increases from Li to Na to K
  D) the elements are in the same period
  Show Answer
  The correct answer is C .
• Question 1478:

  

  The IUPAC name for

  Options:
  A) 2-methylbut-3-ene
  B) 2-methylbut-4-ene
  C) 3-methylbut-2-ene
  D) 3-methylbut-1-ene
  E) 3-methylpent-1-ene
  Show Answer
  The correct answer is D .
• Question 1479:

  

  Use the following option above to answer this question. Which of the following is the functional group of carboxylic acids?

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is D .
• Question 1480: N₂O_4(g)→ 2NO_2(g)In the endothermic reaction above, more products formed will be favored by Options:
  A) A constant values
  B) an increase in pressure
  C) a decrease pressure
  D) a decrease volume
  Show Answer
  The correct answer is C .