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 1841:
  

  Use the section of the periodic table above to answer this question.

  Which of the indicate an alkali metal and a noble gas respectively?

  Options:
  A) M and E
  B) G and E
  C) R and L
  D) G and L
  Show Answer
  The correct answer is D .
• Question 1842: How many valence electrons are contained in the element represented ³¹₁₅P? Options:
  A) 3
  B) 5
  C) 15
  D) 31
  Show Answer
  The correct answer is B .
• Question 1843:

  

  Select the right answer from the structure above.Which of the following compounds represents the polymerization product of ethyne?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 1844: A piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B)when ignited in a crucible produces the oxide of the metal(m). The METAL M is Options:
  A) Zn
  B) Cu
  C) Al
  D) Au
  E) Ca
  Show Answer
  The correct answer is A .
• Question 1845:

  An element, X, forms a volatile hydride XH₃ with a vapour density of 17.0. The relative atomic mass of X is?

  (H = 1)

  Options:
  A) 34.0
  B) 31.0
  C) 20.0
  D) 14.0
  Show Answer
  The correct answer is B .
• Question 1846: Which of these properties gives a solid its definite shape? Options:
  A) strong intermolecular attraction
  B) high melting point
  C) high boiling point
  D) weak intermolecular attraction
  Show Answer
  The correct answer is A .
• Question 1847: Ethene is prepared industrially by Options:
  A) Reforming
  B) Polymerization
  C) Distillation
  D) Cracking
  Show Answer
  The correct answer is D .
• Question 1848: A saturated solution of AgCl was found to have a concentration of 1.30 x 10^-5 mol dm^-3. The solubility product of AgCl therefore is? Options:
  A) 1.30 x 10^-5 mol₂ dm^-6
  B) 1.30 x 10^-7 mol₂ dm^-6
  C) 1.69 x 10^-10 mol₂ dm^-6
  D) 2.60 x 10^-12 mol₂ dm^-6
  Show Answer
  The correct answer is C .
• Question 1849: The main impurity in iron ore during the extraction of iron is Options:
  A) Silicon (IV) oxide
  B) Carbon (IV) oxide
  C) Calcium trioxosilicate
  D) Sulphur (II) oxide
  Show Answer
  The correct answer is A .
• Question 1850: Which is the temperature of a given mass of a gas initially at 0°C and 9 atm, if the pressure is reduced to 3 atm at constant volume? Options:
  A) 91K
  B) 182K
  C) 273K
  D) 819K
  Show Answer
  The correct answer is A .