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 2201: At the same temperature and pressure, 50 cm³ of nitrogen gas contains the same number of molecules as? Options:
  A) 25 cm³ of methane
  B) 40 cm³ of hydrogen
  C) 50 cm³ of ammonia
  D) 100 cm³ of chlorine
  Show Answer
  The correct answer is C .
• Question 2202:

  

  2HCL_(ag) + CaCO_3(ag) → CaCL_2(ag) + H₂O₍₁₎ + CO

  From the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate (IV) as dilute HCL is added to it?

  Options:
  A) L
  B) M
  C) N
  D) P
  Show Answer
  The correct answer is B .
• Question 2203: A liquid begins to boil when? Options:
  A) its vapour pressure is equal to the vapour pressure of its solid at the given temperature
  B) molecules start escaping from its surface
  C) its vapour pressure equals the atmosphere pressure
  D) its volume is sightly increased
  Show Answer
  The correct answer is C .
• Question 2204: Which of the following salts will turn blue litmus red? Options:
  A) Sodium tetrahydroxozincate (ll)
  B) Potassium hydrogentetraoxosulphate (lV)
  C) Sodium trioxocarbonate (lV)
  D) Zinc chloride hydroxide
  Show Answer
  The correct answer is B .
• Question 2205: Group VII elements are Options:
  A) monoatmic
  B) good oxidizing agents
  C) highly electropositive
  D) electron donors
  Show Answer
  The correct answer is B .
• Question 2206: The noble gas, argon,is used for Options:
  A) electric arc welding
  B) welding brass
  C) underwater welding
  D) steel welding
  Show Answer
  The correct answer is A .
• Question 2207:

  Sodium reacts vigorously with water to produce

  Options:
  A) Sodium chloride (NaCl) and oxygen gas (O2)
  B) Sodium nitrate (NaNO3) and water (H2O)
  C) Sodium hydroxide (NaOH) and hydrogen gas (H2)
  D) Sodium oxide (Na2O) and hydrogen gas (H2)
  Show Answer
  The correct answer is C .
• Question 2208: The pollution from petroleum spillage in rivers and lakes can best be dispersed by Options:
  A) Pouring detergents
  B) Passing of ships through the area
  C) Pouring organic solvents
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 2209: An efflorescent compound is a substance that? Options:
  A) absorbs water froom the air without dissolving in it
  B) is capable of giving off coloured luminosity
  C) gives out water to the atmosphere
  D) absorbs water from the air and dissolves in it
  E) gives out its water of crystallization on heating
  Show Answer
  The correct answer is C .
• Question 2210:

  A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?

  Options:
  A) The solution is basic
  B) The solution is neutral
  C) The solution is acidic
  D) The litmus paper is faulty
  Show Answer
  The correct answer is C .