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 1811:

  The products of the thermal decomposition of ammonium trioxonitrate(v) are?

  Options:
  A) Nitrogen (I) Oxide and Water
  B) Ammonia and Oxide
  C) Nitrogen and Water
  D) Nitrogen (IV) Oxide and Water
  Show Answer
  The correct answer is A .
• Question 1812:

  Helium is used in observation of ballons because it is?

  Options:
  A) Light and combustible
  B) light and non-combustible
  C) heavy and combustible
  D) heavy and non-combustible
  Show Answer
  The correct answer is B .
• Question 1813: Zinc and carbon rods are used as anode and cathode respectively in a Options:
  A) Leclanche cell
  B) lead accumulator
  C) Daniel cell
  D) voltaic cell
  Show Answer
  The correct answer is A .
• Question 1814: A suitable solvent for iodine and nephthalene is Options:
  A) carbon (IV) sulphide
  B) ethanol
  C) water
  D) benzene
  Show Answer
  The correct answer is B .
• Question 1815:

  Which separation technique is used to separate different pigments in a mixture based on their affinity for a stationary phase and a mobile phase?

  Options:
  A) Chromatography
  B) Filtration
  C) Decantation
  D) Distillation
  Show Answer
  The correct answer is A .
• Question 1816: Clothes should be properly rinsed with water after bleaching because? Options:
  A) the bleach decolourizes the cothes
  B) chlorine reacts with fabrics during bleaching
  C) the clothes are sterilized during bleaching
  D) hydrogen chloride solution is produced during bleaching
  Show Answer
  The correct answer is D .
• Question 1817: A gas that is not associated with global warming is Options:
  A) CO₂
  B) SO₃
  C) CH₄
  D) H₂
  Show Answer
  The correct answer is A .
• Question 1818: The entropy and enthalpy of a system are a measure of Options:
  A) degree of disorderlinesss and heat content respectively
  B) heat content and degree of disorderliness respectively
  C) heat content of a system only
  D) degree of disorderliness only
  Show Answer
  The correct answer is A .
• Question 1819: Which among the elements 1. Carbon 2. Oxygen 3. Copper 4. Bromine 5. Zinc, will NOT react with either water or steam? Options:
  A) 1 and 2
  B) 2 and 3
  C) 3 and 4
  D) 1, 2, and 3
  E) 2, 3, and 5
  Show Answer
  The correct answer is B .
• Question 1820: The difference between colloides and and suspensions is brought out clearly by the fact that while colloids? Options:
  A) do not scatter light, suspensions do
  B) can be separated by filtration, suspension cannot be so separated
  C) can be separated by a membrane, suspensions cannot
  D) do not settle out on standing, suspensions do
  Show Answer
  The correct answer is D .