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 431:

  Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,

  Options:
  A) P will form an electrovalent bond with R
  B) Q will form a covalent bond with S
  C) R will form an electrovalent bond with S
  D) Q will form an electrovalent bond with S
  Show Answer
  The correct answer is D .
• Question 432:

  Which of the following are chemical changes?

  I. cooking of food
  II. digestion of food
  III. freezing of water
  IV. water is heated up

  Options:
  A) I and II
  B) I, II, and III
  C) III and IV
  D) all of the above
  Show Answer
  The correct answer is A .
• Question 433: 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 434: Stainless steel is used for making Options:
  A) magnets
  B) tools
  C) coins and medals
  D) moving parts of clocks
  Show Answer
  The correct answer is B .
• Question 435:

  The sub-atomic particles located in the nucleus of an atomare?

  Options:
  A) neutron and proton
  B) proton and electron
  C) proton and ions
  D) neutron and electron
  Show Answer
  The correct answer is A .
• Question 436:

  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 437: The radio active radiation used in studying the arrangement of particles in giant organic molecules is Options:
  A) $\gamma$- rays
  B) $\alpha$- particles
  C) X-rays
  D) $\beta$ - particles
  Show Answer
  The correct answer is C .
• Question 438:

  Which of the following pairs of substances will react further with oxygen to form a higher oxide?

  Options:
  A) CO${}_2$ and H${}_2$O
  B) NO and H${}_2$O
  C) CO and CO${}_2$
  D) SO${}_2$ and NO
  Show Answer
  The correct answer is D .
• Question 439: One of the major uses of alkane is Options:
  A) as domestic and industrial fuel
  B) in the hydrogenation of oils
  C) in the textile industries
  D) in the production of plastics
  Show Answer
  The correct answer is A .
• Question 440: mE + nF → pG + qH. In the equation above, the equilibrium constant is given by? Options:
  A) (E)^m(F)ⁿ/ (G)ⁿ(H)^q
  B) (E)(F) / (G)(H)
  C) (G)^p(H)^q / (E)^m(F)ⁿ
  D) (G)(H) / (E)(F)
  Show Answer
  The correct answer is C .