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 861:

  The electronic configuration of element Z is 1s${}^2$ 2s${}^2$ 2p${}^6$ 3s${}^2$ 3p${}^1$. What is the formula of the compound formed between Z and tetraoxosulphate (VI) ion.

  Options:
  A) Z${}_3$(SO${}_4$)${}_2$
  B) ZSO${}_4$
  C) Z${}_2$ SO${}_4$
  D) Z${}_2$(SO${}_4$)${}_3$
  Show Answer
  The correct answer is D .
• Question 862: 25cm³ of a 0.2 mol dm³ solution of Na₂CO₃ requires 20 cm³ of a solution of HCl for neutralization. The concentration of the HCl solution is Options:
  A) 0.5 mol dm³
  B) 0.6 mol dm³
  C) 0.2 mol dm³
  D) 0.4 mol dm³
  Show Answer
  The correct answer is A .
• Question 863:

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

  [ F = 96 5000 C mol^-1 ]

  Options:
  A) 24 125 coulombs
  B) 48 250 coulombs
  C) 72 375 coulombs
  D) 96 500 coulombs
  Show Answer
  The correct answer is B .
• Question 864: According to Charle's law, the volume of a gas becomes zero at Options:
  A) −100°c
  B) −273°c
  C) −373°c
  D) 0°c
  Show Answer
  The correct answer is B .
• Question 865:

  Which quantum divides shells into orbitals?

  Options:
  A) Spin
  B) Principal
  C) Azimuthal
  D) Magnetic
  Show Answer
  The correct answer is C .
• Question 866: Proteins in acid solution undergo Options:
  A) Polymerization
  B) Substitution
  C) Fermentation
  D) Hydrolysis
  Show Answer
  The correct answer is D .
• Question 867: Ammonia gas is normally dried with? Options:
  A) concentrated sulphuric acid
  B) quicklime
  C) anhydrous calcium chloride
  D) magnesium sulphate
  Show Answer
  The correct answer is B .
• Question 868:

  Give the common name for the following compound (CH${}_3$)${}_2$ CH CH${}_2$ -Br

  Options:
  A) Isobutyl bromide
  B) Methyl bromide
  C) propyl bromide
  D) Butyl bromide
  Show Answer
  The correct answer is A .
• Question 869: What volume of oxygen will remain after reacting 8cm³ of hydrogen with 20cm³ of oxygen? Options:
  A) 10 cm³
  B) 12 cm³
  C) 14 cm³
  D) 16 cm³
  Show Answer
  The correct answer is D .
• Question 870: If a gas occupies a container of volume 146 cm³ at 18°C and 0.97`atm, its volume 146cm³ at s.t.p is? Options:
  A) 133
  B) 146
  C) 266
  D) 292
  Show Answer
  The correct answer is A .