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 741:

  The sub-atomic particles located in the nucleus of an atomare?

  Options:
  A) neutron and proton
  B) proton and electron
  C) proton and ions
  D) neutron and electron
  Show Answer
  The correct answer is A .
• Question 742: How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80) Options:
  A) 4. 1 g
  B) 6. 1 g
  C) 8. 1g
  D) 16.2g
  Show Answer
  The correct answer is C .
• Question 743:

  Suitable reagents for the laboratory preparation nitrogen are

  Options:
  A) sodium dioxonitrate(III) and ammonium chloride
  B) sodium trioxonitrate(V) and ammonium chloride
  C) sodium chloride and ammonium trioxonitrate(V)
  D) sodium chloride and ammonium di-ozonitrate(III)
  Show Answer
  The correct answer is A .
• Question 744: Group 1 A metals are not found free in nature because they? Options:
  A) are of low melting and boiling points
  B) have weak metallic bonding
  C) conduct electricity and heat
  D) are very reactive
  Show Answer
  The correct answer is D .
• Question 745:

  Which of the following is a common laboratory indicator for bases?

  Options:
  A) Methyl orange
  B) Phenolphthalein
  C) Bromothymol blue
  D) Litmus
  Show Answer
  The correct answer is B .
• Question 746:

  The substance often used for vulcanization of rubber is?

  Options:
  A) Chlorine
  B) Hydrogen peroxide
  C) Sulphur
  D) Tetraoxosulphate(vi) acid
  Show Answer
  The correct answer is C .
• Question 747: To obtain pure carbon (II) oxide from its mixture with carbon (IV) oxide, the mixture should be Options:
  A) passed over heated copper (II) oxide
  B) bubbled through water
  C) bubbled through concentrated tetroxosulphate (VI) acid
  D) bubbled through sodium hydroxide
  Show Answer
  The correct answer is D .
• Question 748: The furring of kettles is caused by the presence in water of Options:
  A) calcium hydrogentrioxocarbonate (IV)
  B) calcium trioxocarbonate (IV)
  C) calcium tetraoxosulphate (VI)
  D) calcium hydroxide
  Show Answer
  The correct answer is B .
• Question 749:

  N${}_2$O${}_4$⇔ 2NO${}_2$ ( = -ve)

  From the reaction above, which of these conditions would produce the highest equilibrium yield forN${}_2$O${}_4$?

  Options:
  A) Low temperature and high pressure
  B) Low temperature and low pressure
  C) high temperature and low pressure
  D) high temperature and high pressure
  Show Answer
  The correct answer is A .
• Question 750:

  2X_(aq) + MnO_2(s) + 4H⁺_(aq) → X_2(g) + Mn²⁺_(aq) + 2H₂O.

  The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?

  Options:
  A) a poisionous gas
  B) an oxidizing agent
  C) electronegative in nature
  D) highly reactive
  Show Answer
  The correct answer is D .