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 1051: One of the major uses of alkane is Options:
  A) as domestic and industrial fuel
  B) in the hydrogenation of oils
  C) in the textile industries
  D) in the production of plastics
  Show Answer
  The correct answer is A .
• Question 1052:

  A chemical reaction in which the hydration energy is greater than the lattice energy is referred to as

  Options:
  A) A reversible reaction
  B) A spontenous reaction
  C) An endothermic reaction
  D) An exothermic reaction
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  The correct answer is D .
• Question 1053: Oxyacetylene flame is used for iron-welding because it Options:
  A) Makes the iron metals solidify very quickly
  B) Combines with oxygen to give a pop sound
  C) Evolves a lot of heat when burnt
  D) Dissociates to produce carbon (IV) oxide and oxygen
  Show Answer
  The correct answer is C .
• Question 1054:

  In the laboratory preparation of oxygen, the gas cannot be collected by displacement of air because

  Options:
  A) the density of oxygen is greater than that of air
  B) the density of air is nearly the same as that of oxygen
  C) oxygen is a component of air
  D) air is an impure substance
  Show Answer
  The correct answer is A .
• Question 1055: A small quantity of solid ammonium chloride (NH4Cl) texted gently in a test tube, the solid gradually disappear produce two gases. Later, a white cloudy deposit was absence on the cooler part of the test tube. The ammonium chloride is to have undergo Options:
  A) distillation
  B) sublimation
  C) precipitation
  D) evaporation
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  The correct answer is B .
• Question 1056: The salt formed from a weak acid and a strong base hydrolyzes in water to form Options:
  A) A saturated solution
  B) an acidic solution
  C) a buffer solution
  D) an alkaline solution
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  The correct answer is D .
• Question 1057:

  The general formula for the Alkanals is?

  Options:
  A) R${}_2$CO
  B) RCHO
  C) ROH
  D) RCOOR
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  The correct answer is B .
• Question 1058: Hydrogen sulphide gas can act as Options:
  A) an oxidizing agent
  B) a dehydrating agent
  C) a bleaching agent
  D) a precipitating agent
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  The correct answer is D .
• Question 1059:

  N₂O_4(aq) $\rightleftharpoons$ 2NO_2(g) $△$H = +ve

  In the reaction above, an increase in temperature will

  Options:
  A) Increase the reactant production
  B) Increase the value of the equilibrium constant
  C) Shift the equilibrium to the left
  D) Decrease the value of the equilibrium constant
  Show Answer
  The correct answer is B .
• Question 1060: Which of the following compounds will impart a brick-red colour to a non-luminious bunsen flame? Options:
  A) NaCl
  B) LiCl
  C) CaCl₂
  D) MgCl₂
  Show Answer
  The correct answer is C .