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 851: The relative atomic mass of a naturally occurring lithium consisting of 90%$\frac{7}{3}$Li and 10%$\frac{6}{3}$Li is Options:
  A) 6.2
  B) 6.8
  C) 7.1
  D) 6.9
  Show Answer
  The correct answer is D .
• Question 852: Pollution of underground water by metal ions is very likely in the soil that has high Options:
  A) acidity
  B) alkalinity
  C) chloride content
  D) nitrate content
  Show Answer
  The correct answer is B .
• Question 853: Cu₂S_(s) + O2(g) = 2CU_(s) + SO2_2(g) Options:
  A) +1 to 0
  B) 0 to +2
  C) +2 to +1
  D) 0 to +1
  Show Answer
  The correct answer is A .
• Question 854:

  At 25^o and zymase as catalyst,

  C₆H₁₂₆ → 2C₂H₅OH + 2CO₂ + energy

  The reaction above represented by the equation above is useful in the production of

  Options:
  A) propanol
  B) butanol
  C) methanol
  D) ethanol
  Show Answer
  The correct answer is D .
• Question 855:

  Hydrogen diffused through a porous plug

  Options:
  A) thrice as fast as oxygen
  B) at the same speed as oxygen
  C) four times as fast as oxygen
  D) twice as fast as oxygen
  Show Answer
  The correct answer is C .
• Question 856: The component of an atom that contributes least to its mass is the Options:
  A) proton
  B) nucleus
  C) neutron
  D) electron
  Show Answer
  The correct answer is D .
• Question 857: What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke? Options:
  A) Steam distillation
  B) Destructive distillation
  C) Liquefaction
  D) Hydrolysis
  Show Answer
  The correct answer is B .
• Question 858:

  

  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 859: Three drops of a 1.0 mol dm^-3 solution of HCl was added to 20 cm³ of a solution of pH6.4. The pH of the resulting solution will be Options:
  A) close to that of pure water
  B) less than 6.4
  C) greater than 6.4
  D) unaltered
  Show Answer
  The correct answer is B .
• Question 860:

  A metallic oxide which reacts with both HCl and NaOH to give salt and water only can be classified as __________.

  Options:
  A) an acidic oxide
  B) a basic oxide
  C) a neutral oxide
  D) an amphoteric oxide
  Show Answer
  The correct answer is D .