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 1651:

  0.46g of ethanol when burned raised the temperature of 50g of water by 14.3K. Calculate the heat of combustion of ethanol.

  [C = 12, O = 16, H = 1, Specific heat capacity of water = 4.2 jg^-1K^-1]

  Options:
  A) +3000 KJ mol^-1
  B) +300 KJ mol^-1
  C) -300 KJ mol^-1
  D) -3000 KJ mol^-1
  Show Answer
  The correct answer is C .
• Question 1652: Water for town supply is chlorinated to make it free from? Options:
  A) bad odour
  B) bacteria
  C) temporary hardness
  D) permanent hardness
  Show Answer
  The correct answer is B .
• Question 1653:

  CO_(g) + H₂O_(g) → CO_2(g) + H_2(g)

  From the reaction above, calculate the standard enthalpies of formation of CO_2(g), H₂O_(g) and CO_(g) in kJ mol^-1 are -394, -242, and -110 respectively.

  Options:
  A) -262 kJ mol^-1
  B) -42 kJ mol^-1
  C) +42 kJ mol^-1
  D) +262 kJ mol^-1
  Show Answer
  The correct answer is B .
• Question 1654:

  

  The IUPAC nomenclature for the structure above is

  Options:
  A) 2, 3 - dichloro - 4, 4, 5 - trimethyl pent - 2 - ene
  B) 4, 5 - dichloro - 2, 3 - dimethyl hex - 2 - ene
  C) 2, 3 - dichloro - 4, 4 - dimethyl hex - 2- ene
  D) 2, 3 dichloro - 2, 2 - dimethyl hex - 2 - ene
  Show Answer
  The correct answer is C .
• Question 1655:

  A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm³ container at 20°C. The number of moles of gas in the sample is?

  (R = 0.082 litre atm / deg mole)

  Options:
  A) 1.00
  B) 2.00
  C) 3.00
  D) 4.00
  Show Answer
  The correct answer is A .
• Question 1656: What amount of mercury would be liberated if the same quantity of electricity that liberates 0.65g of zinc is applied? Options:
  A) 2.01g
  B) 1.00g
  C) 4.02g
  D) 8.04g
  Show Answer
  The correct answer is C .
• Question 1657:

  What is eutrophication?

  Options:
  A) The release of harmful chemicals into water bodies
  B) The excessive growth of algae due to nutrient enrichment
  C) The presence of heavy metals in water
  D) The formation of oil slicks on water surfaces
  Show Answer
  The correct answer is B .
• Question 1658: Which of the following statement is true of the electrochemical series? Options:
  A) Electropositivity of metals increase down the series
  B) Electropositivity of non-metals decrease down the series
  C) Electronegativity of non-metals decrease down the series
  D) Electropositivity of metals decreases down the series
  Show Answer
  The correct answer is D .
• Question 1659: A cycloalkane with the molecular formula C₅H₁₀ has ? Options:
  A) one isomer
  B) two isomers
  C) three isomers
  D) four isomers
  Show Answer
  The correct answer is C .
• Question 1660:

  

  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 .