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 641: Which of the following gases can be collected by the method of downward delivery? Options:
  A) Chlorine
  B) Oxygen
  C) Ammonia
  D) Hydrogen
  Show Answer
  The correct answer is A .
• Question 642: Chlorine, bromine and iodine resemble one another in that they Options:
  A) dissolve in alkalis
  B) react violently with hydorgen without heating
  C) are liquids
  D) displace one another from solutiions of their salts
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  The correct answer is D .
• Question 643: What mass of sodium carbonate solution is in 500 cm³ of 0.1 molar sodium carbonate solution?(Na = 23, C = 12, O = 16) Options:
  A) 10.6 g
  B) 5.3 g
  C) 500 g
  D) 10 g
  E) 20 g
  Show Answer
  The correct answer is B .
• Question 644:

  

  Use the diagram above to answer this question.

  Which of the following represents a carboxylic acid?

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is A .
• Question 645: When chlorine gas is passed into a solution of sulphur dioxide? Options:
  A) sulphur dioxide is reduced to sulphur
  B) the chlorine is oxidized to hydrochloric acid
  C) dilute sulphuric acid and hydrochloric acid are produced
  D) Hydrochloric acid and sulphur are produced
  E) sulphur trioxide is the only product
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  The correct answer is C .
• Question 646: Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is? Options:
  A) trichloromethane
  B) triodomethane
  C) iodoethane
  D) ethanal
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  The correct answer is B .
• Question 647: 30cm³ of oxygen at 10 atmospheres pressure is placed in a 20 dm³ container. Calculate the new pressure if temperature is kept constant? Options:
  A) 6.7 atm
  B) 15.0 atm
  C) 60.0 atm
  D) 66. 0 atm
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  The correct answer is B .
• Question 648: A sample of orange juice is found to have a PH of 3.80. What is the concentration of the hydroxide ion in the juice? Options:
  A) 1.6 $\times$ 10^-4
  B) 6.3 $\times$ 10^-11
  C) 6.3 $\times$ 10^-4
  D) 1.6 $\times$ 10^-11
  Show Answer
  The correct answer is B .
• Question 649: Which of the following statements is FALSE? Options:
  A) Copper (ll) ion can be reduced to copper (l) ion by hydrochloric acid and zinc
  B) Sodium metal dissolves in water giving oxygen
  C) Nitrogen is insoluble in water
  D) Carbondioxide is soluble in water
  E) lead has a higher atomic weight than copper
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  The correct answer is B .
• Question 650:

  Which of the following pollutants will lead to the depletion of ozone layer?

  Options:
  A) chlorofluorocarbon
  B) carbon (ii) oxide
  C) hydrogen sulphide
  D) sulphur (iv) oxide
  Show Answer
  The correct answer is A .