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 121: Proteins in acid solution undergo Options:
  A) Polymerization
  B) Substitution
  C) Fermentation
  D) Hydrolysis
  Show Answer
  The correct answer is D .
• Question 122: The noble gas, argon, is used for Options:
  A) electrical arc welding
  B) welding brass
  C) underwater welding
  D) steel-welding
  Show Answer
  The correct answer is A .
• Question 123:

  16.55g of lead (ll) trioxonitrate (V) was dissolved in 100g of distilled water at 20^oC, calculate the solubility of the solute in moldm-³

  [Pb = 207, N = 14, O = 16]

  Options:
  A) 0.05 g
  B) 2.00 g
  C) 1.00 g
  D) none of the above
  Show Answer
  The correct answer is D .
• Question 124:

  Which of the following compounds will form a solution if exposed to air?

  Options:
  A) Na₂CO₃.10H₂O
  B) NaNO₃
  C) CuSO₄
  D) CaCl₂
  E) NaSO₄.10H₂O
  Show Answer
  The correct answer is D .
• Question 125: The following arrangement of elements in order of decreasing number of outer electrons; One of the elements is wrongly placed. Which is it? ALUMINIUM, CHLORINE, SILICON, MAGNESIUM AND SODIUM. Options:
  A) chlorine
  B) aluminium
  C) silicon
  D) magnesium
  E) sodium
  Show Answer
  The correct answer is B .
• Question 126: Which of the following noble gases is commonly found in the atmosphere? Options:
  A) Xenon
  B) Neon
  C) Helium
  D) Argon
  Show Answer
  The correct answer is D .
• Question 127: When at equilibrium, which of the reactions below will shift to the right if the pressure is increased and the temperature is kept constant? Options:
  A) 2SO_3(g) ↔ 2SO_2(g) + O_2(g)
  B) 2CO_2(g) ↔ 2CO_(g) + O_2(g)
  C) 2H_2(g) + O_2(g) ↔ 2H₂O_(g)
  D) 2NO_(g) ↔ N_2(g) + O_2(g)
  Show Answer
  The correct answer is C .
• Question 128: Which of the following are the products of the reaction between CH₃COOH and CI₂ in sunlight? Options:
  A) CICH₂COOH + HCI
  B) CH₃COCI + HOCI
  C) CH₃COOCI + HCI
  D) CH₃COCI + HO₂
  Show Answer
  The correct answer is A .
• Question 129:

  Given that 15.00 cm³ of H₂

  SO₄ was required to completely neutralize 25.00 cm³ of 0.125 mol dm^-3 NaOH, calculate the molar concentration of the acid solution:

  Options:
  A) 0.925 mol dm^-3
  B) 0.156mol dm^-3
  C) 0.104 mol dm^-3
  D) 0.023 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 130:

  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 .