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 1461: The maximum number of electrons in the L shell of an atom is Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is B .
• Question 1462: A metallic ion X²⁺ with an inert gas structure contains 18 electrons. How many protons are there in this ion? Options:
  A) 20
  B) 18
  C) 16
  D) 2
  Show Answer
  The correct answer is A .
• Question 1463:

  

  The diagram above best illustrates the effect of decrease in

  Options:
  A) concentration
  B) temperature
  C) surface area
  D) pressure
  Show Answer
  The correct answer is A .
• Question 1464: 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 1465:

  

  The solubility curve of a solid X (molecular mass = 160) is as show above 1,000 cm³ of a saturated solution of X at 80^oC. The weight of X crystalized out would be

  Options:
  A) 10 g
  B) 12 g
  C) 14 g
  D) 16 g
  E) 18 g
  Show Answer
  The correct answer is D .
• Question 1466: H ₂O _(g) + C _(s) → H_2(g) + CO_(g)The oxidizing agent in the reaction above is Options:
  A) CO_(g)
  B) C_(s)
  C) H₂O_(g)
  D) H_(2)(g)
  Show Answer
  The correct answer is C .
• Question 1467:

  On the basis of the electrochemical series, which of these ions will show the greater tendency to be discharged at the cathode in an electrolytic cell

  Options:
  A) cu${}^{2+}$
  B) sn${}^{2+}$
  C) fe${}^{2+}$
  D) zn${}^{2+}$
  Show Answer
  The correct answer is A .
• Question 1468: The conversion of open chain alkanes into cycloalkanes and aromatic compounds is called Options:
  A) cracking
  B) reforming
  C) isomerization
  D) polymerization
  Show Answer
  The correct answer is B .
• Question 1469: The boiling point of water is higher than that of methanol because? Options:
  A) water is oxide while methanol is an alcohol
  B) inter molecular forces in water are stronger than those in methanol
  C) water is an inorganic compound while methanol is organic
  D) water is an ionic compound while methanol is a covalent compound
  E) water is more reactive than methanol
  Show Answer
  The correct answer is B .
• Question 1470: Which of the following is a measure of the average kinetic energy of the molecules of a substance? Options:
  A) Volume
  B) Mass
  C) Pressure
  D) Temperature
  Show Answer
  The correct answer is D .