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 661: To what temperature must a gas 273 K be heated in order to double both its volume and pressure? Options:
  A) 298 K
  B) 546 K
  C) 819 K
  D) 1092 K
  Show Answer
  The correct answer is D .
• Question 662: Which of the following statements is true? Options:
  A) Metals conduct electricity while non-metals do not
  B) Metals have high density, non-metals have low density
  C) Metals form basic oxides, non-metals form acidic oxides
  D) In the electro chemical series, metals are above hydrogen while non-metals are below hydrogen
  E) Metals lose elections while non-metals gain electron during normal reactions
  Show Answer
  The correct answer is C .
• Question 663: Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes? Options:
  A) Oxygen gas is given off at the cathode
  B) Hydrogen gas is given of at the anode
  C) Sodium metals is deposited at the anode
  D) Sodium metal is deposited at the cathode
  E) AAlkalinity at the cathode increases
  Show Answer
  The correct answer is E .
• Question 664: Which of the following ions require the largest quantity of electricity for discharge at an electrode? Options:
  A) 4.0 moles of Cl^-
  B) 3.0 moles of Na⁺
  C) 2.5 moles of Cu²⁺
  D) 2.0 moles of Al³⁺
  Show Answer
  The correct answer is C .
• Question 665: An anhydride is Options:
  A) a compound wich has no water of crystallization
  B) an oxide whose solution in water has a PH greater than 7
  C) an oxide whose solution in water has a PH less than 7
  D) an oxide that has hydrogen atoms
  E) an amphoteric oxide
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  The correct answer is C .
• Question 666: Calculate the relative molecular mass of Limestone CaCO3, (Ca = 40, C =12, O = 16) Options:
  A) 56
  B) 100
  C) 76
  D) 90
  Show Answer
  The correct answer is B .
• Question 667: The general formula of an alkyl halide (where X represents the halide) is? Options:
  A) C_nH_2n2X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  Show Answer
  The correct answer is B .
• Question 668:

  

  In the diagram above, X is the ``

  Options:
  A) enthalpy
  B) enthalpy change
  C) activation energy
  D) activated complex
  Show Answer
  The correct answer is B .
• Question 669:

  P_(g) + Q_(g) ↔ 3R_(s) + S_(g) ΔH is negative

  Which of the following will increase the yield of R?

  Options:
  A) Using a larger close vessel
  B) Increasing the temperature
  C) Removing some S
  D) Adding a positive catalyst
  Show Answer
  The correct answer is C .
• Question 670: Chlorine, bromine and iodine resemble one another in that they Options:
  A) dissolve in alkalis
  B) react violently with hydorgen without heating
  C) are liquids
  D) displace one another from solutiions of their salts
  Show Answer
  The correct answer is D .