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 1301:

  A concentrated solution containing H⁺, Cu²⁺, OH^- and Cl^- was electrolyzed using platinum electrodes.

  The ion that will be discharged at the cathode is

  Options:
  A) Cu²⁺
  B) Cl^-
  C) H⁺
  D) OH^-
  Show Answer
  The correct answer is A .
• Question 1302:

  I. It has a varied composition from one place to another.

  II. It constituents can be separated by physical means.

  III. It contains unreactive noble gases

  Which of the above shows that air is a mixture?

  Options:
  A) I and II only
  B) II and III only
  C) I and III only
  D) I, II and III
  Show Answer
  The correct answer is A .
• Question 1303:

  The heat of reaction can be determined experimentally using a device called a

  Options:
  A) Calorimeter
  B) Barometer
  C) Spectrometer
  D) Thermometer
  Show Answer
  The correct answer is A .
• Question 1304: The product formed when propanol is heated over a copper catalyst in the absence of oxygen are Options:
  A) CH₃CH₂CHO and H₂
  B) CH₃CHO and CO₂
  C) CH₃CH₂COOH and H₂
  D) CH₃COOH and CO₂
  Show Answer
  The correct answer is D .
• Question 1305: Ordinary glass is manufactured from silica, CaCO₃ and Options:
  A) Na₂CO₃
  B) K₂CO₃
  C) K₂SO₄
  D) NaHCO₃
  Show Answer
  The correct answer is A .
• Question 1306:

  

  Use the graph above to answer this question.

  A sample, X, solid at room temperature, was melted, heated to a temperature of 358 K and allowed to cool as shown in OPQR. The section PQ indicates that X is

  Options:
  A) a mixture of salts
  B) a hydrated salt
  C) an ionic salt
  D) a pure compound
  Show Answer
  The correct answer is D .
• Question 1307:

  The reactivity of fluorine is due to?

  Options:
  A) its high electro negativity
  B) small size of fluorine atom
  C) availability of D-orbitals
  D) strong f-f bond
  Show Answer
  The correct answer is A .
• Question 1308: Increasing the pressure of a gas Options:
  A) lowers the average kinetic energy of the molecules
  B) decreases the density of the gas
  C) decreases the temperature of the gas
  D) increases the density of the gas
  E) increases the volume of the gas
  Show Answer
  The correct answer is D .
• Question 1309: Water can be obtained as the only product during the Options:
  A) combustion of hydrocarbons
  B) neutraliization of an acid by base
  C) combustion of hydrogen
  D) electrolysis of brine
  Show Answer
  The correct answer is C .
• Question 1310:

  Sulphur exists in six forms in the solid state. This property is known as

  Options:
  A) Isomerism
  B) Allotropy
  C) Isotopy
  D) Isomorphism
  Show Answer
  The correct answer is B .