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 331: The chemical used for coagulation in water purification is Options:
  A) Aluminium tetraoxosulphate (VI)
  B) Copper tetraoxosulphate (VI)
  C) Sodium tetraoxosulphate (VI)
  D) Calcium tetraoxosulphate (VI)
  Show Answer
  The correct answer is A .
• Question 332:

  Which quantum divides shells into orbitals?

  Options:
  A) Spin
  B) Principal
  C) Azimuthal
  D) Magnetic
  Show Answer
  The correct answer is C .
• Question 333: Which of these properties gives a solid its definite shape? Options:
  A) strong intermolecular attraction
  B) high melting point
  C) high boiling point
  D) weak intermolecular attraction
  Show Answer
  The correct answer is A .
• Question 334: Two elements, P and Q with atomic numbers 11 and 8 respectively , combine chemically to form the compound P_xQ_Y. The respective values of x and y are? Options:
  A) 1 and 1
  B) 1 and 2
  C) 2 and 1
  D) 3 and 1
  Show Answer
  The correct answer is C .
• Question 335: Which of the following ion’s requires the quantity of electricity for discharge at an electrode Options:
  A) 2.0 mole of Q3⁺
  B) 2.5 mole of R2⁺
  C) 3.0 mole of T^-
  D) 4.0 mole of Y^-
  Show Answer
  The correct answer is A .
• Question 336: Which of the following metals does NOT form a stable trioxocarbonate (IV)? Options:
  A) Fe
  B) Al
  C) Zn
  D) Pb
  E) none of the options is correct
  Show Answer
  The correct answer is E .
• Question 337: A compound that will NOT produce oxygen on heating is? Options:
  A) potasium dioxonitrate (III)
  B) lead (IV) oxide
  C) potassium trioxochlorate (V)
  D) potassium trioxonitrate (V)
  Show Answer
  The correct answer is A .
• Question 338:

  

  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 339: In general, an increase in temperature increases the solubility of a solute in water because? Options:
  A) more solute molecules collide with each other
  B) most solutes dissolve with the evoltion of heat
  C) more solute molecules dissociate at hihger temperatures
  D) most solutes dissolve with absorption of heat
  Show Answer
  The correct answer is C .
• Question 340: When sugar is dissolved in tea, the reaction is always accomplished by Options:
  A) positive change
  B) negative entropy change
  C) no entropy change
  D) a minimum entropy change
  Show Answer
  The correct answer is C .