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 861: X_(g) + 3Y_(g) ---- 2z_(g) H = +ve. if the reaction above takes place at room temperature, the G will be Options:
  A) negative
  B) zero
  C) positive
  D) indeterminate
  Show Answer
  The correct answer is D .
• Question 862: Copper and silver metals are commonly use as coin because they are Options:
  A) easily reduced
  B) not easily reduced
  C) easily oxidized
  D) not easily oxidized
  Show Answer
  The correct answer is D .
• Question 863:

  What is the main environmental concern associated with sulfur dioxide emissions?

  Options:
  A) Formation of acid rain
  B) Global warming potential
  C) Depletion of the stratospheric ozone
  D) Depletion of the ozone layer
  Show Answer
  The correct answer is A .
• Question 864: The condition required for corrosion to take place is the presence of Options:
  A) Oxygen and Carbon (IV) oxide
  B) Water and Oxygen
  C) Water and Carbon (IV) oxide and Oxygen
  D) Water and Carbon (IV) oxide
  Show Answer
  The correct answer is B .
• Question 865: In the preparation of ammonia, which of the following is used as the drying agent? Options:
  A) CaO
  B) CaCI₂
  C) Conc. H₂SO₄
  D) P₂O₅
  E) H₃PO₄
  Show Answer
  The correct answer is A .
• Question 866:

  The most abundant rare gas in the atmosphere is?

  Options:
  A) He
  B) Ne
  C) Ar
  D) Xe
  Show Answer
  The correct answer is C .
• Question 867:

  What mass of K₂CrO₄ is required to prepare 250cm³ of 0.020 mol dm³ solution?

  [K₂CrO₄ = 194.2g mol^-1]

  Options:
  A) 0.97g
  B) 9.70g
  C) 19.42g
  D) 97.10g
  Show Answer
  The correct answer is A .
• Question 868: Two hydrocarbons X and Y were treated with bromine water. X decolorised the solution and Y did not not. Which class of compound does Y belong? Options:
  A) Benzene
  B) Alkynes
  C) Alkenes
  D) Alkanes
  Show Answer
  The correct answer is D .
• Question 869:

  C_(s) + H₂O_(g) → H_2(g) + CO_2(g)

  ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is

  Options:
  A) not feasible
  B) at equilibrium
  C) feasible
  D) exothermic
  Show Answer
  The correct answer is C .
• Question 870:

  Which type of chemical combination involves the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions?

  Options:
  A) Ionic bonding
  B) Hydrogen bonding
  C) Covalent bonding
  D) Metallic bonding
  Show Answer
  The correct answer is A .