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 561: Which of the following metals burns with brick red Options:
  A) Pb
  B) Ca
  C) Na
  D) Mg
  Show Answer
  The correct answer is B .
• Question 562:

  

  In the above set up substances X and Y are respectively

  Options:
  A) lime water copper (ll) tetraoxosulphate (lV)
  B) potassium trioxocarbonate and alkaline pyrogallol
  C) potassium hydroxide and alkaline pyrogallol
  D) potassium trioxocarbonate (lV) and concentrated tetraoxosulphate (IV) acid
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  The correct answer is C .
• Question 563:

  Chromatography is used to separate components of mixture which differ in their rates of ?

  Options:
  A) diffusion
  B) migration
  C) reaction
  D) sedimentation
  Show Answer
  The correct answer is B .
• Question 564:

  If a reaction is exothermic and there is a great disorder, it means that

  Options:
  A) the reaction is static
  B) the reaction is in a state of equilibrium
  C) there will be a large increase in free energy
  D) there will be a large decrease in free energy
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  The correct answer is D .
• Question 565: Which of the following statements is FALSE about isotopes of the same element? Options:
  A) They have the same number of electrons in their outermost shells
  B) They have different atomic masses
  C) They have the same atomic number and the number of electrons
  D) They have the same atomic number but different umber of elelctrons
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  The correct answer is D .
• Question 566:

  

  Use the following option above to answer this question. Which of the following is the functional group of carboxylic acids?

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is D .
• Question 567:

  A quantity of electricity liberates 3.6g of Silver from its salt. What mass of aluminium Will be liberated from its salt by the same quantity of electricity? [Al = 27, Ag = 108].

  Options:
  A) 2.7g
  B) 1.2g
  C) 0.9g
  D) 0.3g
  Show Answer
  The correct answer is A .
• Question 568: 2.25g of a sample of an oxide of copper on reduction gave 2.0g of copper. 2.50g of another oxide of copper on reduction also gave 2.0g of copper. These results are in accordance with the law of? Options:
  A) constant composition
  B) conservation of matter
  C) multiple proportions
  D) definite proportions
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  The correct answer is C .
• Question 569: If excess zinc is added to a bluish green solution of copper (II) sulphate, and the excess zinc filtered off after completion of reaction, a colourless solution is obtained because Options:
  A) both zinc and copper are metals
  B) the sulphate radical and the zinc ion are divalent
  C) zinc is more electropositive than copper
  D) both zinc and copper form depositive ions in solution
  E) zinc is a reducing agent
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  The correct answer is C .
• Question 570:

  An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contains is

  Options:
  A) 16
  B) 15
  C) 46
  D) 31
  Show Answer
  The correct answer is B .