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 1041:

  C₃H₅ - COH₃ =CH₂

  The IUPAC nomenclature of the structure above is

  Options:
  A) 3-methybut-3-ene
  B) 2-methylbut-1-ene
  C) 2-ethylprop-1-ene
  D) 2-methylbut-2-ene
  Show Answer
  The correct answer is B .
• Question 1042: How many unpaired electron are in the p-orbitals of a fluorine atom? Options:
  A) 3
  B) $0$
  C) 1
  D) 2
  Show Answer
  The correct answer is C .
• Question 1043: Which are the correct IUPAC names for H-CO₂CH₃ and CH = CH Options:
  A) Methyl methanoate and ethene
  B) Metanoic acid and ethyne
  C) Ethyl methanoate and ethyne
  D) Methyl methanoate and ethyne
  E) Ethanoic acid and ethene
  Show Answer
  The correct answer is A .
• Question 1044:

  The volume occupied by 1.58g of a gas at S.T.P is 500cm${}^3$. What is the relative molecular mass of the gas?  [ G.M.V at S.T.P = 22.4dm${}^3$ ]

  Options:
  A) 28
  B) 32
  C) 44
  D) 71
  Show Answer
  The correct answer is D .
• Question 1045: Which of the following is used in the manufacture of bleaching powder? Options:
  A) Sulphur dioxide
  B) Chlorine
  C) Hydrogen tetraoxosulphate (VI)
  D) Hydrogen sulphide
  E) Nitrogen dioxide
  Show Answer
  The correct answer is B .
• Question 1046:

  An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

  Reaction of X with yeast forms the basis of the

  Options:
  A) plastic industry
  B) textile industry
  C) brewing industry
  D) soap industry
  E) dyeing industry
  Show Answer
  The correct answer is C .
• Question 1047: What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g? Options:
  A) 62.5 g
  B) 40.0 g
  C) 6.3 g
  D) 2.5 g
  Show Answer
  The correct answer is A .
• Question 1048: The general formula of an alkyl halide (where X represents the halide) is? Options:
  A) C_nH_2n2X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  Show Answer
  The correct answer is B .
• Question 1049: A suitable reagent for distinguish between ethanoic and ethanol is Options:
  A) bromine water
  B) Fehling’s solution
  C) sodium hydrogen trioxocarbonate (iv)
  D) Ammoniacal silver trioxonitrate(V)
  Show Answer
  The correct answer is C .
• Question 1050: Unsaturated organic compounds are identified by decolourization of Options:
  A) silver bromine and potassium tetraoxomanganate (VII) solutions
  B) bromine water and acidified potassium tetraoxomanganate (VII) solution
  C) silver bromide solution and bromine water
  D) bromine water and alkaline potassium tetraoxomanganate (VII) solution
  Show Answer
  The correct answer is B .