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 1691: 25cm³ of a 0.2 mol dm³ solution of Na₂CO₃ requires 20 cm³ of a solution of HCl for neutralization. The concentration of the HCl solution is Options:
  A) 0.5 mol dm³
  B) 0.6 mol dm³
  C) 0.2 mol dm³
  D) 0.4 mol dm³
  Show Answer
  The correct answer is A .
• Question 1692: The process of converting starch to ethanol is Options:
  A) cracking
  B) distillation
  C) fermentation
  D) oxidation
  Show Answer
  The correct answer is C .
• Question 1693:

  Which type of salt is found in antacid medications and is used to relieve heartburn and indigestion?

  Options:
  A) Aluminum chloride
  B) Magnesium chloride
  C) Sodium chloride
  D) Calcium chloride
  Show Answer
  The correct answer is B .
• Question 1694: 200 cm³ of a gas at 25^oC exerts a pressure of 700 mmHg. Calculate its pressure if its volume increase 350 cm³ at 75^oC. Options:
  A) 342.53 mmHg
  B) 1430.54 mmHg
  C) 467.11 mmHg
  D) 400.00 mmHg
  Show Answer
  The correct answer is C .
• Question 1695: H ₂O _(g) + C _(s) → H_2(g) + CO_(g)The oxidizing agent in the reaction above is Options:
  A) CO_(g)
  B) C_(s)
  C) H₂O_(g)
  D) H_(2)(g)
  Show Answer
  The correct answer is C .
• Question 1696: Metalliods are also referred to as Options:
  A) semi-metals
  B) metals
  C) colliods
  D) non-metals
  Show Answer
  The correct answer is A .
• Question 1697: All these are electromagnetic waves except Options:
  A) White light
  B) Photon
  C) X-ray
  D) Infrared
  Show Answer
  The correct answer is B .
• Question 1698:

  The maximum electron in N shell is?

  Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is D .
• Question 1699:

  CU₂S_(s) + O_2(g) → 2CU_(s) + SO_2(g)

  What is the change in the oxidation number of copper in the reaction above?

  Options:
  A) +1 to 0
  B) 0 to +2
  C) +2 to +1
  D) 0 to +1
  Show Answer
  The correct answer is A .
• Question 1700: Which of the following compounds is NOT formed by the action of chlorine on methane? Options:
  A) CH₃CI
  B) C₂H₅CI
  C) CH₂CI₂
  D) CHCI₃
  Show Answer
  The correct answer is B .