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 891: An elements X with relative atomic mass 16.2 contains two isotopes ¹⁶₈X with relative abundance of 90% and ^m₈X with relative abundance of 10%. The value of m is Options:
  A) 16
  B) 18
  C) 12
  D) 14
  Show Answer
  The correct answer is B .
• Question 892: The experiment that showed that atoms have tiny positively charged nucleus was first carried out by Options:
  A) Moseley
  B) Rutherford
  C) Millikan
  D) Dalton
  Show Answer
  The correct answer is B .
• Question 893: Temporary hard water is formed when rain water containing dissolved carbon(IV) oxide flows over deposits of Options:
  A) CaCO₃
  B) Na₂CO₃
  C) Na₂SO₄
  D) CaSO₄
  Show Answer
  The correct answer is A .
• Question 894:

  

  From the diagram above, an ideal can be represented by

  Options:
  A) M
  B) N
  C) K
  D) L
  Show Answer
  The correct answer is B .
• Question 895: Complete oxidation of propan -1- ol gives? Options:
  A) propanal
  B) propan-2-al
  C) propan-1-one
  D) propanoic acid
  Show Answer
  The correct answer is D .
• Question 896:

  

  The diagram above represents an atom that can combine with chlorine to form

  Options:
  A) a covalent bond
  B) an electrovalent bond
  C) a hydrogen bond
  D) a co-ordinate bond
  Show Answer
  The correct answer is B .
• Question 897: Which of the following types of reactions takes place between C₂H₄ and the halogens? Options:
  A) Substitution
  B) Polymerization
  C) Addition
  D) Saponification
  E) Oxidation
  Show Answer
  The correct answer is C .
• Question 898:

  Which of the following metals is commonly alloyed with copper to make brass?

  Options:
  A) Iron
  B) Nickel
  C) Aluminum
  D) Zinc
  Show Answer
  The correct answer is D .
• Question 899: Alloys are often used in preference to pure metals because? Options:
  A) metals are too hard
  B) merals are ductile
  C) metallic properties are improve in alloys
  D) alloys are a mixture of metals
  Show Answer
  The correct answer is C .
• Question 900: In an equilibrium reaction, which of the following conditions indicates that maximum yield of the product will be obtained? Options:
  A) Equilibrium constant is very large
  B) ∆H - T∆S = O
  C) ∆ H > T ∆ S
  D) Equilibrium constant is less than zero
  Show Answer
  The correct answer is A .