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 1761: 0.499g 0f CuSO₄.xH₂O when heated to constant weight gave a residue of 0.346g. the value of x is? (Cu = 63.5, S = 32.0, O = 16, H = 1) Options:
  A) 0.5
  B) 2.0
  C) 3.0
  D) 4.0
  E) 5.0
  Show Answer
  The correct answer is D .
• Question 1762: Crude petroleum pollutant usually seen on some Nigerian creeks and waterways can be dispersed or removed by Options:
  A) heating the affected parts in order to boil off the petroleum
  B) mechanically stirring to dissolve the petroleum in water
  C) pouring organic solvents to dissolve the petroleum
  D) spraying the water with stergents
  E) cooling to freeze out the petroleum
  Show Answer
  The correct answer is C .
• Question 1763: Which of the following samples will react fastest with dilute trioxonitrate (V) acid? Options:
  A) 5 g of lumps of CacO₃ at 25°C
  B) 5 g of powered CacO₃ at 25°
  C) 5 g of lumps of CaCO₃ at 50°C
  D) 5 g of powered CaCO₃ AT 50°C
  Show Answer
  The correct answer is D .
• Question 1764: One note of a hydrocarbon 36g of carbon and its density is 20. The structure of hydrocarbon is (organic chemical) Options:
  A) CH3C = CH
  B) CH3CH = CH2
  C) CH3CH2C = CH
  D) CH33CH2CH3
  Show Answer
  The correct answer is A .
• Question 1765: What is the volume of oxygen required to burn complete 45 cm³ of methane at s.t.p? Options:
  A) 135.0 cm³
  B) 180.0 cm³
  C) 45.0 cm³
  D) 90.0 cm³
  Show Answer
  The correct answer is D .
• Question 1766:

  Calculate the mass of chlorine gas which occupies a volume of 1.12dm³ at s.t.p

  [Cl = 35.5, molar volume of gas at s.t.p = 22.4 dm³

  Options:
  A) 15.50 g
  B) 7.10 g
  C) 3.55 g
  D) 1.80 g
  Show Answer
  The correct answer is C .
• Question 1767:

  

  The I.U.P.A.C name for the compound is

  Options:
  A) isopropylethene
  B) acetylene
  C) 3- methylbutane
  D) 2-methylbutane
  E) 5-methylpentane
  Show Answer
  The correct answer is D .
• Question 1768: 35 cm³ of hydrogen was sparked with 12 cm³ of oxygen at 110°C and 760mm Hg to produce steam. What percentage of the total volume of gas left after the reaction is hydrogen? Options:
  A) 11%
  B) 31%
  C) 35%
  D) 69%
  Show Answer
  The correct answer is B .
• Question 1769:

  What is the solubility product constant (Ksp) used for?

  Options:
  A) To measure the total mass of a solute that can dissolve in a solvent
  B) To determine the concentration of a solute in a saturated solution
  C) To calculate the solubility of a solute in a given solvent
  D) To compare the solubilities of different solutes in the same solvent
  Show Answer
  The correct answer is B .
• Question 1770:

  Which of the following types of bonding does not involve the formation of new substances?

  Options:
  A) Metallic
  B) Covalent
  C) Co-ordinate
  D) Electrovalent
  Show Answer
  The correct answer is A .