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 1011:

  What is the solubility product constant (Ksp) used for?

  Options:
  A) To measure the total mass of a solute that can dissolve in a solvent
  B) To determine the concentration of a solute in a saturated solution
  C) To calculate the solubility of a solute in a given solvent
  D) To compare the solubilities of different solutes in the same solvent
  Show Answer
  The correct answer is B .
• Question 1012:

  Na${}_2$CO${}_3$ + 2HCl $\to$ 2NaCl + H${}_2$O + CO${}_2$

  The indicator most suitable for this reaction should have a pH equal to

  Options:
  A) 5
  B) 7
  C) 3
  D) 9
  Show Answer
  The correct answer is C .
• Question 1013: The type of reaction that is peculiar to benzene is Options:
  A) addition
  B) hydrolysis
  C) polymerization
  D) substitution
  Show Answer
  The correct answer is D .
• Question 1014: When ethanol is heated with excess concentrated sulphuric acid, the ethanol is? Options:
  A) oxidized to ethene
  B) polymerized to polyethene
  C) dehydrated to ethene
  D) dehydrated to ethyne
  Show Answer
  The correct answer is C .
• Question 1015: Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because Options:
  A) zinx is not rendered passive by acid
  B) hydrogen produced is oxidized to water
  C) oxides of nitrogen are produced
  D) all nitrates are soluble in water
  E) trioxonitrate(v)acid is a strong acid
  Show Answer
  The correct answer is E .
• Question 1016:

  A 'breath test' used by traffic police to check drunken driving uses?

  Options:
  A) Tumeric on filter paper
  B) Silica gel coated with saliva nitrate
  C) Potassium permanganate-sulphuric acid
  D) Potassium dichromatic-sulphuric acid
  Show Answer
  The correct answer is D .
• Question 1017:

  The compounds made up of only carbon and hydrogen are called?

  Options:
  A) Carbon compounds
  B) Hydrocarbons
  C) Atoms
  D) Carbon hydrolysis
  Show Answer
  The correct answer is B .
• Question 1018:

  On the basis of the electrochemical series, which of these ions will show the greater tendency to be discharged at the cathode in an electrolytic cell

  Options:
  A) cu${}^{2+}$
  B) sn${}^{2+}$
  C) fe${}^{2+}$
  D) zn${}^{2+}$
  Show Answer
  The correct answer is A .
• Question 1019:

  The number of electrons in the valence shell of an element of atomic number 14 is?

  Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is D .
• Question 1020: The Avogadro number of 24g of magnesium is the same as that of Options:
  A) 1g of hydrogen molecules
  B) 16g of oxygen molecules
  C) 32g of oxygen molecules
  D) 35.5g of chlorine molecules
  Show Answer
  The correct answer is C .