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 651: H^- + H_2(I)O → H_2(g) + OH^-_(aq). From the equation above, it can be inferred that the? Options:
  A) reaction is a double decomposition
  B) hydride ion is a reducing agent
  C) hydride ion is an oxidizing agent
  D) reaction is neutralization
  Show Answer
  The correct answer is B .
• Question 652: Which of the following is not a member of the homologous series of the paraffins (alkanes)? Options:
  A) C₃H₈
  B) C₅H₁₂
  C) C₇H₁₆
  D) C₁₅H₃₂
  E) C₂₄H₄₈
  Show Answer
  The correct answer is E .
• Question 653:

  The solubility of the solids that dissolves in a given solvent with the liberation of heat will

  Options:
  A) increase with an increase in temperature
  B) decrease with an increase in temperature
  C) decrease with a decrease in temperature
  D) not be affected by changes in temperature
  Show Answer
  The correct answer is A .
• Question 654:

  The lanthanides and actinides are located in which block of the periodic table?

  Options:
  A) P-block
  B) S-block
  C) F-block
  D) D-block
  Show Answer
  The correct answer is C .
• Question 655:

  

  The appropriate test paper to use in the above experiment is moist

  Options:
  A) litmus psper
  B) potassium heptaoxodichromate (IV) paper
  C) lead (ll) trioxonitrate (V) paper
  D) universal indicator paper
  Show Answer
  The correct answer is C .
• Question 656: The gas that is removed by the water in the flask is Options:
  A) O ₂
  B) SO ₂
  C) HCI
  D) H ₂
  Show Answer
  The correct answer is C .
• Question 657: The radio active radiation used in studying the arrangement of particles in giant organic molecules is Options:
  A) $\gamma$- rays
  B) $\alpha$- particles
  C) X-rays
  D) $\beta$ - particles
  Show Answer
  The correct answer is C .
• Question 658: How many faraday of electricity is required to produce 0.25 mole of copper? Options:
  A) 1.00F
  B) 0.01F
  C) 0.05F
  D) 0.50F
  Show Answer
  The correct answer is D .
• Question 659:

  Which of the following factors will speed up the rate of evolution of carbon (iv) oxide in the reaction below?

  2HCl + CaCO${}_3$ → CaCl${}_2$ + H${}_2$O + CO${}_2$

  Options:
  A) Increasing the concentration of the acid
  B) Increasing the surface area of CaCO${}_3$
  C) A and B
  D) Reducing the concentration of the acid
  Show Answer
  The correct answer is C .
• Question 660: Sodium metal is always kept under oil because it Options:
  A) Readily reacts with water
  B) Is reduced by atmospheric nitrogen
  C) Reacts vigorously on exposure to air
  D) Reacts with oxygen and carbon (IV) oxide
  Show Answer
  The correct answer is C .