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 891:

  How many electrons will be found in the nucleus of an atom with mass number 23 and 17 neutrons?

  Options:
  A) none
  B) 6
  C) 7
  D) 8
  Show Answer
  The correct answer is A .
• Question 892: which of the following polymers is suitable for packaging and electrical insulation? Options:
  A) polyamide
  B) polyethene
  C) polycarbonate
  D) polystyrene
  Show Answer
  The correct answer is D .
• Question 893: If the electron configuration of a element is p1s² 2s² 2P⁵, how many unpaired electron are there? Options:
  A) 2
  B) 8
  C) 1
  D) 4
  Show Answer
  The correct answer is C .
• Question 894:

  At room temperature and standard pressure, chlorine gas is in which state of matter?

  Options:
  A) Plasma
  B) Solid
  C) Liquid
  D) Gas
  Show Answer
  The correct answer is D .
• Question 895: A solution which on treatment with hydrochloric acid produces a colourless, odourless gas which turns lime water milky is most likely to be a Options:
  A) trioxonitrate (V)
  B) chloride
  C) trioxocarbonate (IV)
  D) hydroxide
  Show Answer
  The correct answer is C .
• Question 896: How many faraday of electricity is required to produce 0.25 mole of copper? Options:
  A) 1.00F
  B) 0.01F
  C) 0.05F
  D) 0.50F
  Show Answer
  The correct answer is D .
• Question 897: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They have different number of carbon atoms
  B) They are members of same homologous series
  C) They have the same boiling points
  D) They have the same chemical properties
  Show Answer
  The correct answer is D .
• Question 898: The pollutant that contributes to the depletion of the ozone layer is Options:
  A) CFCs
  B) NO₂
  C) SO₂
  D) CO
  Show Answer
  The correct answer is A .
• Question 899: The equilibrium of an endothermic reaction which proceeds with an increase in volume can be shifted in the reverse direction by Options:
  A) increasing the temperature and decreasing the pressure
  B) increasing the pressure and increasing the temperature
  C) decreasing the temperature and increasing the pressure
  D) decreasing the pressure and decreasing the temperature
  Show Answer
  The correct answer is C .
• Question 900:

  If the volume of a given mass of a gas at 0ºc is29.5cm${}^3$. What will be the volume of the gas at 15ºc, given that the pressure remains constant.

  Options:
  A) 31.6
  B) 62.2
  C) 32.7
  D) 31.1
  Show Answer
  The correct answer is D .