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 951:

  1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁷, 4s²

  An element with the electronic configuration above is a

  Options:
  A) non-metal
  B) metal
  C) transition element
  D) group two element
  Show Answer
  The correct answer is C .
• Question 952:

  What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?

  Options:
  A) C${}_4$H${}_8$O${}_4$
  B) CH${}_2$O
  C) C${}_2$H${}_4$O${}_2$
  D) C${}_3$H${}_6$O${}_3$
  Show Answer
  The correct answer is B .
• Question 953: In the electrolysis of brine the anode is Options:
  A) platinum
  B) copper
  C) zinc
  D) carbon
  Show Answer
  The correct answer is D .
• Question 954:

  

  The IUPAC nomenclature for the compound above is

  Options:
  A) dimethlhexane
  B) 3,5 dimethylhexane
  C) 1.1 dmethyl, 3 methylpentane
  D) 2.4 dimethylhexane
  Show Answer
  The correct answer is D .
• Question 955:

  The combustion of carbon(ii)oxide in oxygen can be represented by equation.

  2CO + O${}_2$ → 2CO${}_2$

  Calculate the volume of the resulting mixture at the end of the reaction if 50cm${}_3$ of carbon(ii)oxide was exploded in 100cm${}_3$ of oxygen

  Options:
  A) 75cm${}^3$
  B) 125cm${}^3$
  C) 100cm${}^3$
  D) 50cm${}^3$
  Show Answer
  The correct answer is B .
• Question 956:

  Give the common name for the following compound (CH${}_3$)${}_2$ CH CH${}_2$ -Br

  Options:
  A) Isobutyl bromide
  B) Methyl bromide
  C) propyl bromide
  D) Butyl bromide
  Show Answer
  The correct answer is A .
• Question 957: How many isomeric forms are there for the molecular formula C₃H₆Br₂? Options:
  A) 1
  B) 2
  C) 3
  D) 4
  E) 5
  Show Answer
  The correct answer is D .
• Question 958: If chlorine gas is bubbled into water and then this yellowish-green coloured solution is exposed to bright sunlight for a while Options:
  A) the solution will give out chlorine gas and hydrogen chloried gas
  B) the solution will produce chlorine gas and oxygen
  C) the solution will give out solution will producing hypochloric acid
  D) the solution is decomposed giving out oxygen, hydrogen and chlorine
  E) the solution will give out oxygen gas leaving behind aqueous hydrochloric acid
  Show Answer
  The correct answer is E .
• Question 959:

  The boiling of fat and aqueous caustic soda is referred to as

  Options:
  A) hydrolysis
  B) esterification
  C) acidification
  D) saponification
  Show Answer
  The correct answer is D .
• Question 960: Smog usually occurs over cities which Options:
  A) burn a lot of fossil fuels
  B) have very few plants
  C) are surrounded by water
  D) are overpopulated
  Show Answer
  The correct answer is A .