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 1701:

  What is the PH of 0.00 1 moldm${}^3$ solution of the sodium hydroxide

  Options:
  A) 14
  B) 13
  C) 12
  D) 11
  Show Answer
  The correct answer is D .
• Question 1702: According to the kinetic theory an absence in temperature causes the kinetic energy of particles to Options:
  A) decrease
  B) increase
  C) remain constant
  D) be zero
  Show Answer
  The correct answer is D .
• Question 1703:

  

  In the diagram above , the activation energy for the backward reaction is

  Options:
  A) +5kJ
  B) +15KJ
  C) +25KJ
  D) +30KJ
  Show Answer
  The correct answer is C .
• Question 1704: Ethanol reacts with concentrated tetraoxosulphate (V) acid at a temperature above 170 ^oC to form Options:
  A) ethanone
  B) ethene
  C) ethyne
  D) ethanal
  Show Answer
  The correct answer is B .
• Question 1705: The molar ratio of oxygen to nitrogen in dissolved air is 2:1 whereas the ratio is 4:1 in atmospheric air because? Options:
  A) nitrogen is less soluble than oxygen
  B) oxygen is heavier than nitrogen
  C) nitrogen has a higher partial pressure in air
  D) gases are hydrated in water
  Show Answer
  The correct answer is A .
• Question 1706:

  Liquid black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the

  Options:
  A) Acid
  B) Ester of alkanoic acid
  C) Alkali
  D) Alkanol
  Show Answer
  The correct answer is C .
• Question 1707:

  Which of the following can be obtained by fractional distillation? 

  Options:
  A) Nitrogen from liquid air
  B) Sodium Chloride from sea water
  C) Iodine from solution of Iodine in carbon tetrachloride
  D) Sulphur from the solution of sulphur in carbon disulphide
  Show Answer
  The correct answer is A .
• Question 1708: The principle of column chromatography is based on th ability of the constituents to Options:
  A) React with the solvent in the column
  B) React with each other in the solvent in the column
  C) Dissolve in each other in the column
  D) Move at different speeds in the column
  Show Answer
  The correct answer is D .
• Question 1709: Neutral atoms of neon with atomic number 10 have the same number of electron as Options:
  A) O²⁺
  B) Ca²⁺
  C) K⁺
  D) Mg²⁺
  Show Answer
  The correct answer is D .
• Question 1710: 20 cm ³ of hydrogen gas are sparked with 20cm ³ of oxygen gas in an endimoeter at 373k (100 ^oC) and 1 atmosphere. The resulting mixture is cooled to 298 K (25 ^oC) and passed over calcium chloride. The volume of the residual gas is Options:
  A) 40 cm ³
  B) 20 cm ³
  C) 30 cm ³
  D) 10cm ³
  E) 5cm ³
  Show Answer
  The correct answer is D .