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 511: The general formula of an alkyl halide (where X represents the halide) is? Options:
  A) C_nH_2n2X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  Show Answer
  The correct answer is B .
• Question 512: Which of the following compounds is used as a gaseous fuel? Options:
  A) CH₃ -CH₂ -CHO₂ -COOH
  B) CH₃ -C = CH
  C) CH₃ -CH₂ -CH₂ -CH₃
  D) CH₂ -CH₂ -CH₃
  Show Answer
  The correct answer is C .
• Question 513: Which of the following statement is true of a proton? Options:
  A) The mass of a proton is 1840 times the mass of electron
  B) the total mass of the protons in a particular nucleus is always half the nuclear size
  C) The mass of a proton is one - twelfth the molar mass of carbon
  D) The mass of a proton is 1.0008g
  Show Answer
  The correct answer is D .
• Question 514: 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 515: POlyvinyl chloride is used to produce Options:
  A) bread
  B) pencils
  C) ink
  D) pipes
  Show Answer
  The correct answer is D .
• Question 516:

  If acidified Potassium Dichromate(VI) (K${}_2$Cr${}_2$O${}_7$) acts as oxidizing agent, color changes from

  Options:
  A) yellow to green
  B) orange to green
  C) yellow to red
  D) orange to red
  Show Answer
  The correct answer is B .
• Question 517: The bleaching action of chlorine gas is effective due to the presence of Options:
  A) hydrogen chloride
  B) water
  C) air
  D) oxygen
  Show Answer
  The correct answer is B .
• Question 518: the minimum amount of energy required for a reaction to take place is Options:
  A) lattice energy
  B) ionization energy
  C) activation energy
  D) kinetic energy
  Show Answer
  The correct answer is C .
• Question 519: P1V1 = P2V2 supports ? Options:
  A) Charles’s law
  B) Boyles’s law
  C) Graham’s law
  D) Avogadro’s law
  Show Answer
  The correct answer is B .
• Question 520: Alloys are best prepared by Options:
  A) electroplating
  B) Arc-welding
  C) reducing and mixture of their metallic
  D) cooking a molten of the metals
  Show Answer
  The correct answer is D .