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 1381: The reaction between ethanoic acid and sodium hydroxide is an example of Options:
  A) esterification
  B) neutralization
  C) hydroxylation
  D) hydrolysis
  Show Answer
  The correct answer is B .
• Question 1382: Which of these gases can be dried with concentrated H₂SO₄? Options:
  A) HBr
  B) H₂S
  C) NH₃
  D) SO₂
  Show Answer
  The correct answer is A .
• Question 1383: A substance that is used as a ripening agent for fruits is Options:
  A) ethene
  B) propene
  C) methane
  D) butane
  Show Answer
  The correct answer is A .
• Question 1384: On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as Options:
  A) efflorescence
  B) diliquescence
  C) hygroscopy
  D) hydrolysis
  Show Answer
  The correct answer is A .
• Question 1385: Neutralization involves a reaction between H₃O⁺ and? Options:
  A) CI^-
  B) OH^-
  C) NO₃^-
  D) CO₃^2-
  Show Answer
  The correct answer is B .
• Question 1386: If the silver mirror test is positive, it indicates the presence of an Options:
  A) alkyne
  B) alkanol
  C) alkanone
  D) alkanal
  Show Answer
  The correct answer is D .
• Question 1387: zn + 2HCl → ZnCl₂ + H₂The rate of the above reaction will be greatly increased if Options:
  A) the zinc is in the powered form
  B) a greater volume of the acid is used
  C) a smaller volume of the acid is used
  D) the reaction vessel is immersed in an ice-bath
  E) the zinc is in the form of pellets
  Show Answer
  The correct answer is A .
• Question 1388: The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0) Options:
  A) N₂O₂
  B) NO
  C) NO₂
  D) N₂O
  E) N₂O₃
  Show Answer
  The correct answer is C .
• Question 1389:

  For the reaction NH₄NO₂ $\to$ N₂ + 2H₂O, calculate the volume of nitrogen that would be produced at S. T. P from 320 g of the dioxonitrate(iii)salt. (Relative atomic masses: N = 14, O = 16, H = 1)

  Options:
  A) 2.24 dm ³
  B) 224 dm³
  C) 1.12 dm ³
  D) 112 dm ³
  E) 4.48 dm ³
  Show Answer
  The correct answer is D .
• Question 1390: The most abundant element on the earth's crust is Options:
  A) nitrogen
  B) hydrogen
  C) oxygen
  D) flourine
  Show Answer
  The correct answer is C .