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 2271: In order to remove one electron from a 3S orbital of gaseous sodium atom, about 496KJMol^-1 of energy is required. This energy is referred to as Options:
  A) electron affinity
  B) ionization energy
  C) activation evergy
  D) electronegativity
  Show Answer
  The correct answer is B .
• Question 2272: Which of the following will react further with oxygen to form higher oxide? Options:
  A) NO and H₂O
  B) CO and CO₂
  C) SO₂ and NO
  D) CO₂ and H₂O
  Show Answer
  The correct answer is C .
• Question 2273: The energy value of petrol can be determined by Options:
  A) Bomb calorimeter
  B) Catalytic cracker
  C) Fractionating column
  D) Thermometer
  Show Answer
  The correct answer is C .
• Question 2274: When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by? Options:
  A) bubbling it through concentrated H₂SO₂
  B) bubbling it through water and then passing it through calcium oxide
  C) passing it directly through calcium oxide
  D) passing it directly through calcium chloride
  Show Answer
  The correct answer is C .
• Question 2275:

  What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?

  Options:
  A) 24,125 C
  B) 48,250 C
  C) 72,375 C
  D) 96,500 C
  Show Answer
  The correct answer is B .
• Question 2276: The processes which return carbon (IV) oxide to the atmosphere include Options:
  A) respiration, decay and combustion
  B) photosynthesis, respiration and transpiration
  C) ozone depletion, combustion and decay
  D) photosynthesis, decay and respiration
  Show Answer
  The correct answer is A .
• Question 2277: A gas exerts pressure on its container because Options:
  A) the molecules of a gas collide with the walls of the container
  B) some of the molecules are moving faster than others
  C) of the collisions of the molecules with each other
  D) of the mass of the molecules of the gas
  Show Answer
  The correct answer is A .
• Question 2278: In titration involving sodium hydroxide and dilute hydrochloric acid, where would you place the base? Options:
  A) in the beaker
  B) in the conical flask
  C) in a burette
  D) in the standard flask
  E) in the measuring cylinder
  Show Answer
  The correct answer is B .
• Question 2279:

  

  The functional group represented in the compound above is

  Options:
  A) alkanol
  B) alanal
  C) alkanone
  D) alanoate
  Show Answer
  The correct answer is C .
• Question 2280:

  Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.
  The relative abundance of the isotope of mass number 37 is?

  Options:
  A) 20
  B) 25
  C) 50
  D) 75
  Show Answer
  The correct answer is B .