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 1371: The solution with the lowest pH value is Options:
  A) 5 ml of (m/10) HCL
  B) 10 ml of (m/10) HCL
  C) 15 ml of (m/5) HCL
  D) 20 ml of (m/8) HCL
  Show Answer
  The correct answer is A .
• Question 1372:

  Elements in the periodic table are arranged in the order of their

  Options:
  A) atomic numbers
  B) metallic character
  C) mass number
  D) relative atomic mass
  Show Answer
  The correct answer is A .
• Question 1373: Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI? Options:
  A) All the metals
  B) Mg ,Fe and Cu
  C) Mg, Fe and Pb
  D) Mg and Fe only
  E) Mg only
  Show Answer
  The correct answer is D .
• Question 1374:

  What is the sum of the oxidation numbers in a neutral compound?

  Options:
  A) +2
  B) -1
  C) 0
  D) +1
  Show Answer
  The correct answer is C .
• Question 1375: 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 1376: What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together? Options:
  A) A white precipitate is formed
  B) A green precipitate is formed
  C) The mixture remains colourless
  D) The mixture turns reddish brown
  Show Answer
  The correct answer is D .
• Question 1377:

  

  The above orbital diagram shown the electronic configuration of

  Options:
  A) chlorine
  B) nitrogen
  C) calcium
  D) neon
  Show Answer
  The correct answer is B .
• Question 1378:

  What type of reaction is involved in the formation of alkanols from alkenes?

  Options:
  A) Elimination reaction
  B) Redox reaction
  C) Substitution reaction
  D) Addition reaction
  Show Answer
  The correct answer is D .
• Question 1379: The dispersion of a liquid in a liquid medium will give Options:
  A) an emulsion
  B) a fog
  C) a gel
  D) an aerosol
  Show Answer
  The correct answer is A .
• Question 1380:

  The equilibrium reaction between copper (l) chloride and chlorine at 25^oC and 1 atmosphere is represented by the equation:

  2CuCl +Cl₂ ⇌ 2 CuCl₂ ∆H = - 166 KJ. Which of the following statements is TRUE for the reaction, pressure remaining constant?

  Options:
  A) more CuCl is formed at 40^oC
  B) more CuCl₂ is formed at 10^oC
  C) Less CuCl₂ is formed at 10^oC
  D) there is no change in the amount of CuCl₂ formed at 40^oC and10^oC
  E) more CuCl is consumed at 40^oC
  Show Answer
  The correct answer is B .