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 1281: An example of an alcohol is Options:
  A) CCl₄
  B) CH₃COOH
  C) CHCl₃
  D) C₂H₆
  E) CH₃OH
  Show Answer
  The correct answer is E .
• Question 1282: A common characteristic shared by iron and aluminium is that both? Options:
  A) are extracted by reduction methods
  B) form only basic oxides
  C) show oxidation states of +2 and +3
  D) form soluble hydroxides
  Show Answer
  The correct answer is A .
• Question 1283: Cr₂O₇ + 6Fe²⁺ + 14H⁺ → 2Cr³⁺ +6Fe³⁺ + 7H₂O. In the above , the oxidation number of chromium changed from? Options:
  A) +7 to +3
  B) +6 to +3
  C) +5 to +3
  D) -2 to +3
  Show Answer
  The correct answer is A .
• Question 1284:

  What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?

  Options:
  A) Liquid
  B) Solid
  C) Plasma
  D) Gas
  Show Answer
  The correct answer is D .
• Question 1285: 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 1286: An oxidation state of or in K2CrO7 Options:
  A) 7
  B) 6
  C) 5
  D) 4
  Show Answer
  The correct answer is B .
• Question 1287: What volume of 0.5 MH₂SO₄ will exactly neutralize 20cm³ of 0.1 MNaOH Solution? Options:
  A) 2.0cm³
  B) 5.0cm³
  C) 6.8cm³
  D) 8.3cm³
  Show Answer
  The correct answer is A .
• Question 1288: Which of the following physical properties decreases across the Periodic Table? Options:
  A) Ionization potenial
  B) Electron affinity
  C) Electronegativity
  D) Atomic radius
  Show Answer
  The correct answer is D .
• Question 1289: Which of the following reactions does not take place in the smelting of iron in a blast furnace? Options:
  A) CaCO_3(s) CaO_(s) + CO_2(g)
  B) C_(s) + O_2(g) CO_2(g)
  C) 3FeCO_(s) + 2OCO_2(g) FeO_4(s)
  D) SiO_2(s) + CaO_(s) CaCO_3(s)
  E) CO_2(g) + C_(s) 2CO_(g)
  Show Answer
  The correct answer is C .
• Question 1290: The product formed when propanol is heated over a copper catalyst in the absence of oxygen are Options:
  A) CH₃CH₂CHO and H₂
  B) CH₃CHO and CO₂
  C) CH₃CH₂COOH and H₂
  D) CH₃COOH and CO₂
  Show Answer
  The correct answer is D .