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 261: Which of the following represents ethyl ethanonate? Options:
  A) CH₃CH₂CO₂CH₃
  B) (CH₃CO₂)₂O
  C) CH₃CH₂CO₂CH₂CH₃
  D) CH₃CO₂CH₂CH₃
  E) CH₃CH₂COCH₂CH₃
  Show Answer
  The correct answer is D .
• Question 262: 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 263: The products of the combustion of candle wax are Options:
  A) hydrogen and water
  B) oxygen and water
  C) carbon (IV) oxide and water
  D) carbon (II) oxide and water
  Show Answer
  The correct answer is C .
• Question 264: Which is the temperature of a given mass of a gas initially at 0°C and 9 atm, if the pressure is reduced to 3 atm at constant volume? Options:
  A) 91K
  B) 182K
  C) 273K
  D) 819K
  Show Answer
  The correct answer is A .
• Question 265:

  

  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 266: 60cm³ of hydrogen are sparked with 20cm³ of oxygen at 100^oC and 1 atmosphere . The total volume of the residual gases in Options:
  A) 60 cm³
  B) 10 cm³
  C) 40 cm³
  D) 30 cm³
  E) 70 cm³
  Show Answer
  The correct answer is A .
• Question 267: If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form? Options:
  A) Dative
  B) Covalent
  C) Lonic
  D) Metallic
  Show Answer
  The correct answer is C .
• Question 268: Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes? Options:
  A) Oxygen gas is given off at the cathode
  B) Hydrogen gas is given of at the anode
  C) Sodium metals is deposited at the anode
  D) Sodium metal is deposited at the cathode
  E) AAlkalinity at the cathode increases
  Show Answer
  The correct answer is E .
• Question 269: The postulate of Dalton's atomic theory which still holds is that Options:
  A) atoms can neither be created nor destroyed
  B) the particles of the same element are exactly alike
  C) particles of different elements combine in simple whole number ratio
  D) all elemets are made of small indivisible particles
  Show Answer
  The correct answer is A .
• Question 270:

  Zn_(s) + CuSO_4(aq) $\to$ ZnSO_4(aq) + Cu_(s)

  In the reaction above, the oxidizing agent is

  Options:
  A) CuSO_4(aq)
  B) ZnSO_4(aq)
  C) Cu_(s)
  D) Zn_(s)
  Show Answer
  The correct answer is A .