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 971: The fuming of kettles is caused by the presence in the water of Options:
  A) calcium tetraoxosulphate (IV)
  B) calcium hydrogentrionocarbonate (IV)
  C) calcium hydroxide
  D) calcium trioxocarbonate (IV)
  Show Answer
  The correct answer is B .
• Question 972:

  The only metal that is anti-bacterial is?

  Options:
  A) Iron
  B) Sodium
  C) Alluminium
  D) Copper
  Show Answer
  The correct answer is D .
• Question 973: The stability of the noble gases is due to the fact that they Options:
  A) have no electron in their outermost shells
  B) have duplet or octet electron configurations
  C) belong to group zero of the periodic table
  D) are volatile in nature
  Show Answer
  The correct answer is B .
• Question 974: 20 cm³ of 1.0 molar NH₄OH solution when neutralized with 20.05cm³ of 0.1 molar HCl liberated -102 joules of heat. Calculate the heat of neutralization of NH₄OH? Options:
  A) -51.O KJ mol^-
  B) +57.3 KJ mol^-
  C) +57.O KJ mol^-
  D) +51.0 KJ mol^-
  Show Answer
  The correct answer is A .
• Question 975: An acid is said to be weak if? Options:
  A) its ions are so completely dissociated that they easily drift apart
  B) the acid is not corrosive
  C) the acid has low specific gravity
  D) its ions move very slowly when in solution
  E) its ions are incompletely dissociated
  Show Answer
  The correct answer is E .
• Question 976:

  

  Use the table above to answer this question. The element that is likely to participate in covalent rather than ionic bonding is

  Options:
  A) Z
  B) Y
  C) X
  D) W
  Show Answer
  The correct answer is C .
• Question 977:

  I. Treatment of cancerII. Detection of leakages in water mainsIII. Detection of the ages of ancient toolsIV. Preparation of drugs

  Which combination of the above refers to the uses of radioactive isotopes?

  Options:
  A) I and III
  B) I and II
  C) I, II and III
  D) I, II, III and IV
  Show Answer
  The correct answer is C .
• Question 978:

  The densities of two gases, X and Y, are 0.5 g dm^-3 and 2.0 dm^-3 respectively.

  What is the rate of diffusion of X relative to Y?

  Options:
  A) 0.1
  B) 0.5
  C) 2.0
  D) 4.0
  Show Answer
  The correct answer is C .
• Question 979: The element with the electron configuration 1s²2s²2p³ is Options:
  A) calcium
  B) chlorine
  C) oxygen
  D) nitrogen
  Show Answer
  The correct answer is D .
• Question 980:

  N₂O_4(g) ↔ 2NO_2(g) ΔH = +ve

  In the reaction above, an increase in temperature will

  Options:
  A) increase the value of the equilibrium constant
  B) decreases the value of the equilibrium constant
  C) increase in the reactant production
  D) shift the equilibrium to the left
  Show Answer
  The correct answer is A .