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 941: Which of the following bonds exist in crystalline ammonium chloride (NH₄Cl)? Options:
  A) Ionic and covalent
  B) Ionic and co-ordinate
  C) Ionic covalent and co-ordinate
  D) Covalent , co-ordinate and metalllic
  E) Ionic, covalent and metallic
  Show Answer
  The correct answer is C .
• Question 942: which of the following metals will show the highest metallic character? Options:
  A) Zinc
  B) Copper
  C) Barium
  D) Calcium
  Show Answer
  The correct answer is D .
• Question 943: If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form? Options:
  A) Dative
  B) Covalent
  C) Lonic
  D) Metallic
  Show Answer
  The correct answer is C .
• Question 944: During the vulcanization of rubber, sulphur is added to Options:
  A) Break down rubber polymer
  B) Lengthen the chain of rubber
  C) Bind rubber molecules together
  D) Act as a catalyst
  Show Answer
  The correct answer is C .
• Question 945:

  Which of the following reactions is an oxidation process?

  Options:
  A) 2H${}^{+}$ + 2e${}^{-}$ $\to$ H${}_2$
  B) 2O${}^{2-}$ + 4e${}^{-}$ $\to$ O${}_2$
  C) OCl${}^{-}$ + H${}_2$O + 2e${}^{-}$ $\to$ 2OH${}^{-}$ + Cl${}^{-}$
  D) Cl + e${}^{-}$ $\to$ Cl${}^{-}$
  Show Answer
  The correct answer is B .
• Question 946: Increasing the pressure of a gas Options:
  A) lowers the average kinetic energy of the molecules
  B) decreases the density of the gas
  C) decreases the temperature of the gas
  D) increases the density of the gas
  E) increases the volume of the gas
  Show Answer
  The correct answer is D .
• Question 947: If 100cm³ of oxygen pass through a porous plug is 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is? [O = 16, H = 1] Options:
  A) 10.0s
  B) 12.5s
  C) 17.7s
  D) 32.0s
  Show Answer
  The correct answer is B .
• Question 948:

  

  Use the above option to answer this question. The dehydration of ammonium salt of alkanoic acids produces a compound with the general formula

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 949:

  

  The IUPAC nomenclature of the organic compound with the above structural formula is

  Options:
  A) 3-ethyl-2,5-dimethylhexane
  B) 4-ethyl-2,5-dimethylhexane
  C) 3-ethyl-2,5,5 - trimethylpentane
  D) 3-ethyl, 1,1,4-trimethylpentane
  Show Answer
  The correct answer is A .
• Question 950: In the course of an experiment, two gases X and Y were produced. X turned wet lead ethanoate to black and Y bleached moist litmus paper. What are the element(s) in each of the gases X and Y respectively? Options:
  A) H and S;Cl
  B) H and O;Cl
  C) H and S;C and O
  D) H and Cl;S and O
  Show Answer
  The correct answer is A .