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 2291:

  The following compounds are given with their corresponding boiling points.

  Compound Boiling Point

  i.................................14°C

  ii................................24°C

  iii................................0°C

  iv................................120°C

  V.................................-2°C

  From the above information, indicate which of the following is correct?

  Options:
  A) All the compounds are gaseous at 20 °C
  B) One of the compounds is gaseous at 20 °C
  C) Two of the compounds are gaseous at 20 °C
  D) Three of the compounds are gaseous at 20 °C
  E) None of the compounds is gaseous at 20 °C
  Show Answer
  The correct answer is D .
• Question 2292: If glucose is heated on the concentration tetraoxosulphate(iv)acid, it will be dehydrated Options:
  A) carbon
  B) carbon(iv)oxide
  C) ethane
  D) ethanol
  Show Answer
  The correct answer is A .
• Question 2293: In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity? Options:
  A) Ethanoic acid, milk or magnesia, sodium chloride, hydrochloric acid and sodium hydroxide
  B) Ethanoic acid, hydrochloric acid, milk of magnesia, sodium chloride and sodium chloride and sodium hydroxide
  C) Hydrochloride acid, ethanol acid, sodium chloride, milk of magnesia and sodium hydroxide
  D) Hydrochloride acid, sodium hydroxide sodium chloride, ethanol acid, and milk of magnesia
  Show Answer
  The correct answer is C .
• Question 2294:

  In the preparation of oxygen by heating KCIO, in the presence of MnO${}_2$ only moderate heat is needed because the catalyst acts by ${}_2$

  Options:
  A) lowering the pressure of the reaction
  B) increasing the surface area of the reaction
  C) increasing the rate of the reaction
  D) lowering the energy barrier of the reaction
  Show Answer
  The correct answer is D .
• Question 2295: 25 cm³ of 0.02 M KOH neutralized 0.03 g of a monobasic organic acid having the general formula C_nH_{2n + 1} COOH. The molecular formula of the acid is?(C = 12, H = 1, O = 16) Options:
  A) HCOOH
  B) C₂H₅COOH
  C) CH₃COOH
  D) C₃H₇COOH
  Show Answer
  The correct answer is C .
• Question 2296:

  

  In the diagram above the gas Y could be

  Options:
  A) hydrogen chloride
  B) oxygen
  C) carbon (IV) oxide
  D) chlorine
  Show Answer
  The correct answer is A .
• Question 2297: Which of the following statement is correct about the periodic table? Options:
  A) Elements in the same period have the same number of valency electron
  B) The valence electron of the elements in the same period increase progressively across the period
  C) Elements in the same group have the same number of electron shells
  D) The non-metallic properties of the elements tend to decrease across each period
  Show Answer
  The correct answer is B .
• Question 2298: The synthetic detergents are preferred to soap for laundry using hard water because? Options:
  A) detergents are water soluble while soap is not
  B) the calcium salts of detergents are water soluble
  C) the magnesium salt of soap is soluble in hard water
  D) soap does not have a hydrocarbon terminal chain
  Show Answer
  The correct answer is B .
• Question 2299: 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 2300: 5 block elements of the periodic table one made up of Options:
  A) groups 1, 2, 3
  B) groups 1, and 2
  C) group 3
  D) group 3 to 7
  Show Answer
  The correct answer is B .