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 241: The approximate volume of air containing 10cm³ of oxygen is? Options:
  A) 20 cm³
  B) 25 cm³
  C) 50 cm³
  D) 100 cm³
  Show Answer
  The correct answer is C .
• Question 242: The weakest attractive force that can be observed between two molecules is Options:
  A) ionic
  B) covalent
  C) co-ordinate covalent
  D) vander Waals
  Show Answer
  The correct answer is D .
• Question 243:

  

  The IUPAC nomenclature for the compound above is

  Options:
  A) 4-methylpent-1-ene
  B) 3-methylpent-2-ene
  C) 2-methylpent-1ene
  D) 2-methylpent-4-ene
  Show Answer
  The correct answer is A .
• Question 244:

  A secondary alkanol can be oxidized to give an

  Options:
  A) alkanone
  B) alkyne
  C) alkanoic acid
  D) alkanal
  Show Answer
  The correct answer is A .
• Question 245: Detergents are more advantageous than soaps in hard water districts because Options:
  A) on treatment with hard water they either form soluble calcium salts or do not react with calcium ion
  B) on treatment with hard water they form soluble calcium salts
  C) on treatment with hard water they form sodium salts
  D) on treatment with hard water they are converted into soaps
  E) on treatment with hard water they form more lather than soaps does
  Show Answer
  The correct answer is A .
• Question 246:

  

  Use the solubility curves below to answer questions. If 1 dm³ of a saturated solution of L at 60⁰C is cooled to 25⁰C, what amount in mole will separate out?

  Options:
  A) 0.75
  B) 0.25
  C) 1.00
  D) 0.50
  Show Answer
  The correct answer is A .
• Question 247:

  Burning magnesium ribbon in air removes which of the following

  (i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?

  Options:
  A) i and iv only
  B) i, ii, iii and iv only
  C) i only
  D) i and ii only
  Show Answer
  The correct answer is C .
• Question 248:

  

  Use the table above to answer this question. The element that is likely to participate in covalent rather than ionic bonding is

  Options:
  A) Z
  B) Y
  C) X
  D) W
  Show Answer
  The correct answer is C .
• Question 249:

  Identify the reducing agent in the following reaction:
  Zn + CuSO${}_4$ ZnSO${}_4$ + Cu

  Options:
  A) Cu
  B) Zn
  C) ZnSO${}_4$
  D) CuSO${}_4$
  Show Answer
  The correct answer is B .
• Question 250:

  How many atoms are present in 6.0g of magnesium? [Mg = 24, N.A = 6.02 x 10 ${}^{23}$mol]

  Options:
  A) 1.20 x 10${}^{22}$
  B) 2.4 x 10${}^{22}$
  C) 1.51 x 10${}^{22}$
  D) 3.02 x 10${}^{22}$
  Show Answer
  The correct answer is C .