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 1041:

  

  The diagram represents

  Options:
  A) A spontaneous reaction
  B) An exothermic reaction
  C) A non-spontaneous
  D) An endothermic reaction
  Show Answer
  The correct answer is C .
• Question 1042:

  What weight of NaCl is needed to make 2.0 dm³ of a 1.5M solution?

  [Na = 23, Cl = 35.5]

  Options:
  A) 116 g
  B) 175 g
  C) 87 g
  D) 58 g
  Show Answer
  The correct answer is B .
• Question 1043: How many isomers does pentane have? Options:
  A) 6
  B) 5
  C) 4
  D) 3
  Show Answer
  The correct answer is D .
• Question 1044: When chlorine Is passed into water and the resulting solution exposed to sunlight, the product formed are Options:
  A) Chlorine gas and hydrogen
  B) Oxygen and oxochlorate (I) acid
  C) Chlorine gas and oxochlorate (I) acid
  D) Hydrochloric acid and oxygen
  Show Answer
  The correct answer is D .
• Question 1045: Which of the following terms indicates the number of bonds that can be formed by an atom? Options:
  A) Oxidation number
  B) Valence
  C) Atomic number
  D) Electronegativity
  Show Answer
  The correct answer is B .
• Question 1046: 25 cm³ of 0.02 M KOH neutralized 0.03 g of a monobasic organic acid having the general formula C_nH_{2n + 1} COOH. The molecular formula of the acid is?(C = 12, H = 1, O = 16) Options:
  A) HCOOH
  B) C₂H₅COOH
  C) CH₃COOH
  D) C₃H₇COOH
  Show Answer
  The correct answer is C .
• Question 1047: Sodium and potassium belong to the same group of the Periodic Table. This is because? Options:
  A) both are metals
  B) both are soft and lighter than water
  C) both form cations by losing electrons
  D) both have identical electronic configuration
  E) both react with water vigorously
  Show Answer
  The correct answer is D .
• Question 1048: Rare gases are suitable because they Options:
  A) are monoatomic
  B) form ions easily
  C) have duplet or octet electronic configuration in the outermost shells in their atoms
  D) are volatile gases
  Show Answer
  The correct answer is C .
• Question 1049:

  On which of the following is the solubility of a gaseous substance dependent? 

  I. Nature of solvent 

  II. Nature of solute 

  III. Temperature 

  IV. Pressure

  Options:
  A) I, II, III and IV
  B) I and II only
  C) II only
  D) I, III and IV only
  Show Answer
  The correct answer is D .
• Question 1050:

  Which group does calcium belong to in the periodic table?

  Options:
  A) Alkaline earth metals
  B) Halogens
  C) Alkali metals
  D) Noble gases
  Show Answer
  The correct answer is A .