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 811: If 24.4 g of lead (ll) trioxonitrate (V) were dissolved in 42 g of distilled water at 20^oC; calculate the solubility of the solute in gdm^-3. Options:
  A) 581.000.
  B) 0.581
  C) 5.810
  D) 58.100
  Show Answer
  The correct answer is A .
• Question 812:

  

  The I.U.P.A.C name for the compound

  Options:
  A) 2-methyl-3-pentene
  B) 4-methyl-2-pentane
  C) 2-methyl-2-pentene
  D) 4-methylpent-2-ene
  E) 2-methyl-3-pentane
  Show Answer
  The correct answer is D .
• Question 813:

  Using the metal activity series, the metal that can liberate hydrogen gas from steam is?

  Options:
  A) iron
  B) copper
  C) tin
  D) lead
  Show Answer
  The correct answer is A .
• Question 814: Hardness of water is caused by the presence of ions of Options:
  A) magnesium and silver
  B) cacium and magnesium
  C) sodium and potassium
  D) calcium and sodium
  Show Answer
  The correct answer is B .
• Question 815: Which of the following substances is a basic salt? Options:
  A) Na₂CO₃
  B) Mg(OH)CI
  C) NaHCO₃
  D) KSO₄.AI₂(SO₄)₃,24H₂O
  Show Answer
  The correct answer is B .
• Question 816: Which of the following ions will give a white precipitate with aqueous NaOH and soluble in excess of the base? Options:
  A) Ca²⁺
  B) Mg²⁺
  C) Zn²⁺
  D) Cu²⁺
  Show Answer
  The correct answer is C .
• Question 817: The energy change (ΔH) for the reaction CO(g) + (1)/(2)O_2(g) → is?(ΔHi(CO) = -110.4 kJ mol^-) (ΔHi(CO₂) = -393 kJ mol^-) Options:
  A) -503.7 kJ
  B) +503.7kJ
  C) -282.9 kJ
  D) +282.9 kJ
  E) +393.3 kJ
  Show Answer
  The correct answer is C .
• Question 818: The industrial preparation of hydrogen gas from water gas is referred to as Options:
  A) Bosch process
  B) Contact process
  C) Haber process
  D) Bayer Process
  Show Answer
  The correct answer is A .
• Question 819: Two metallic ions associated with hard water are Options:
  A) copper and zinc
  B) magnesium and silver
  C) calcium and magnesium
  D) potassium and tin
  E) sodium and lead
  Show Answer
  The correct answer is C .
• Question 820: Which of the following raw materials would be required from the smelting of iron ore in a blast furnace? Options:
  A) CaCO ₃
  B) Zn(NO₃)₂
  C) CuSO₄
  D) AICI₃
  E) CaSO₄
  Show Answer
  The correct answer is A .