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 1171:

  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 1172: Substance employed as drying agents are usually Options:
  A) amphoteric
  B) hydroscopic
  C) efflorescent
  D) acidic
  Show Answer
  The correct answer is B .
• Question 1173:

  Which of the following will give a precipitate with an aqueous solution of copper (I) chloride?

  Options:
  A) But-2-ene
  B) But-1-ene
  C) But-2-yne
  D) But-1-yne
  Show Answer
  The correct answer is D .
• Question 1174: A particle that contains 9 protons, 10 neutrons and 10 electrons is a Options:
  A) negative ion
  B) positive ion
  C) neutral atom of non-metal
  D) neutral atom of a metal
  Show Answer
  The correct answer is A .
• Question 1175: Which of the following, in clear solution, forms a white precipitate when carbon (IV) oxide is bubbled into it for a short time? Options:
  A) KOH
  B) NaOH
  C) Ca(OH)₂
  D) AI(OH)₃
  Show Answer
  The correct answer is C .
• Question 1176: Which of the following compounds is composed of Al, Si, O and H? Options:
  A) Epsom salt
  B) Limestone
  C) Clay
  D) Urea
  Show Answer
  The correct answer is C .
• Question 1177: Which of the following has an isomer? Options:
  A) C₆H₆
  B) C₂H₆
  C) C₄H₁₀
  D) C₂H₄
  Show Answer
  The correct answer is C .
• Question 1178:

  What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution? [Na = 23, O =16, H = 1]

  Options:
  A) 0.40 moldm${}^{-3}$
  B) 0.50 moldm${}^{-3}$
  C) 0.05 moldm${}^{-3}$
  D) 0.30 moldm${}^{-3}$
  Show Answer
  The correct answer is B .
• Question 1179:

  N_2(g) + O_2(g) ↔ 2NO_(g); ΔH = + 180.6 kJ mol^-1

  In the reaction above, increase in temperature will

  Options:
  A) increase the quantity of N₂
  B) increase in the yield of NO
  C) decrease the yield of NO
  D) decrease the quantity of O₂
  Show Answer
  The correct answer is B .
• Question 1180:

  

  The compound above exhibits

  Options:
  A) Geometric isomerism
  B) Positional isomerism
  C) Structural isomerism
  D) Optical isomerism
  Show Answer
  The correct answer is D .