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 2121: The greater the different in electronegativity between bonded atoms, the? Options:
  A) lower the polarity of the bond
  B) higher the polarity of the bond
  C) weaker the bond
  D) higher the possibility of the substance formed being a molecule
  Show Answer
  The correct answer is C .
• Question 2122: Which of the following statements about phosphorus is NOT correct? Options:
  A) Phosphorus is a solid mineral
  B) Phosphorus is obtained by oxidation reaction of phosphate
  C) Phosphorus exists in two allotropic forms
  D) Both forms of phosphorus are interconvertible
  E) Yellow phosporus ignites when rubbed on a rough surface
  Show Answer
  The correct answer is E .
• Question 2123: Which group of elements forms hydrides that are pyramidal in structure? Options:
  A) III
  B) IV
  C) V
  D) VI
  Show Answer
  The correct answer is C .
• Question 2124: Which of the following questions is correct about the periodic table? Options:
  A) The non-metallic properties of the elements tend to decrease across each period
  B) The valence electrons of the elements increase progressively across the period
  C) Elements in the same group have the same numbeer of electron shells
  D) Elements in the same period have the number of valence electrons
  Show Answer
  The correct answer is B .
• Question 2125:

  The size (diameter) of five elements are in the order R < T < W < X < Y, Y being the largest. If each atom has an electron situated on its circumference, and neglecting other factors, which of the atoms will lose its electron most reluctantly?

  Options:
  A) R
  B) T
  C) W
  D) X
  E) Y
  Show Answer
  The correct answer is A .
• Question 2126: The salt that will form a precipitate soluble in excess ammonia solution is Options:
  A) Ca(NO₃)₂
  B) Cu(NO₃₎₂
  C) Mg(NO₃₎₂
  D) Al(NO₃₎₃
  Show Answer
  The correct answer is B .
• Question 2127:

  In which of the following will hydrogen form ionic compound?

  Options:
  A) HCL
  B) NaH
  C) NH${}_3$
  D) CH${}_4$
  Show Answer
  The correct answer is B .
• Question 2128: A mixture of ethanol, sodium dichromate, and water is allowed to drop gradually into a boiling solution containing one part concentrated H₂SO
  ₄ and the liberate gas is collected by cooling it with ice water to give a liquid. This liquid is? Options:
  A) ethanoic acid
  B) acetaldehyde
  C) ethyl acetate
  D) methanol
  E) ethylene
  Show Answer
  The correct answer is A .
• Question 2129: Air boiled out of water as steam is richer in Options:
  A) nitrogen and oxygen
  B) carbon (IV) oxide and oxygen
  C) noble gases and carbon (IV) oxide
  D) oxygen and noble gases
  Show Answer
  The correct answer is B .
• Question 2130:

  

  Choose the correct answer in the option above.

  Which of the following is a primary amine?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .