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 data in the table above shows the rate of reaction of nitrogen (ll) oxide with chlorine at 25^oC It can be concluded that doubling the initial concentration of NO increase the rate of reaction by a factor of

  Options:
  A) two
  B) three
  C) four
  D) five
  Show Answer
  The correct answer is C .
• Question 512: Which experiment led to the measurement of the charge on an electron? Options:
  A) Mass spectrometric experiment
  B) Oil-drop experiment
  C) Scattering α - particles
  D) Discharge-tube experiment
  Show Answer
  The correct answer is B .
• Question 513: Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with Options:
  A) silver nitrates solution, a white precipates insoluble in dilute HNO₃
  B) barium chloride solution, a white precipitate insoluble in dilute H₂SO₄
  C) barium chloride solution, a white precipitate insoluble in dilute HCl
  D) barium chloride solution a white precipitate soluble in dilute ammonia
  E) barium chloride solution a white precipitate insoluble in dilute HCl
  Show Answer
  The correct answer is C .
• Question 514:

  

  The graph above demonstrate the effect of

  Options:
  A) surface area on the rate of reaction
  B) catalyst on the rate of reaction
  C) pressure on the rate reaction
  D) concentration on the rate of reaction
  Show Answer
  The correct answer is A .
• Question 515: 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 516:

  The solubility of the solids that dissolves in a given solvent with the liberation of heat will

  Options:
  A) increase with an increase in temperature
  B) decrease with an increase in temperature
  C) decrease with a decrease in temperature
  D) not be affected by changes in temperature
  Show Answer
  The correct answer is A .
• Question 517: The ability of carbon to form long chains is referred to as Options:
  A) Alkylation
  B) Acylation
  C) Carbonation
  D) Catenation
  Show Answer
  The correct answer is D .
• Question 518: Which of the following can have an isomer? Options:
  A) C₂H₄
  B) C₄H₁₀
  C) C₃H₈
  D) C₂H₆
  E) C₆H₆
  Show Answer
  The correct answer is B .
• Question 519: The oxidation state of chlorine in potassium chlorate is Options:
  A) +1
  B) +2
  C) +3
  D) +5
  E) +7
  Show Answer
  The correct answer is D .
• Question 520:

  CH₃ - CH₂ - C CH

  The hybridization in the compound above is

  Options:
  A) Sp²
  B) sp
  C) sp³ and sp²
  D) sp³ and sp
  Show Answer
  The correct answer is D .