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 1581: In the laboratory preparation of trioxonitrate (V) acid the nitrogen(iv) oxide formed as a by-product is removed by Options:
  A) further heating
  B) adding concentrated H₂SO₄
  C) cooling the acid solution with cold water
  D) bubbling air through the acid solution
  Show Answer
  The correct answer is D .
• Question 1582:

  In the reaction N₂(g) + O(g) ↔ 2NO(g) produced an increase in the total pressure will?

  Options:
  A) cause less nitrogen to be produced in the equilibrium mixture
  B) cause less nitric oxide to be produced in the equilibrium mixture
  C) cause more nitric oxide to be produced in the equilibrium mixture
  D) cause more oxygen to be produced in the equilibrium mixture
  E) have no effect
  Show Answer
  The correct answer is E .
• Question 1583:

  The process or act of extracting a metal from its ore and refining it is called?

  Options:
  A) Extraction
  B) Metal mining
  C) Mettallurgy
  D) Prospecting
  Show Answer
  The correct answer is C .
• Question 1584: An example of aromatic compound is? Options:
  A) C₆H₁₃OH
  B) C₆H₁₃CI
  C) C₆H₅OH
  D) C₆H₁₄
  Show Answer
  The correct answer is C .
• Question 1585: (1 /(2) N_2(g) + (1) / (2)O_2(g) → NO_(g) ∆H° 89 KJ mol^-. If the entropy change for the reaction above at 25°C is 11.8 J mol^-, calculate the change in free energy. ∆G°, for the reaction at 25°C? Options:
  A) 88.71 KJ
  B) 85.48 KJ
  C) -204.00 KJ
  D) -3427.40 KJ
  Show Answer
  The correct answer is D .
• Question 1586: The carbon atoms in ethene are? Options:
  A) sp³ hybridized
  B) sp hybridized
  C) sp² hybridized
  D) not hybridized
  Show Answer
  The correct answer is C .
• Question 1587: The air pollutant unknown in nature is Options:
  A) NO
  B) CO
  C) HCHO
  D) DDT
  Show Answer
  The correct answer is D .
• Question 1588: The most abundant element on the earth's crust is Options:
  A) nitrogen
  B) hydrogen
  C) oxygen
  D) flourine
  Show Answer
  The correct answer is C .
• Question 1589: The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is? Options:
  A) sodium
  B) chlorine
  C) hydrogen
  D) sodium hydroxide
  E) oxygen
  Show Answer
  The correct answer is C .
• Question 1590: Which of the following is an electrolyte? Options:
  A) alcohol
  B) sodium ethanoate
  C) solid potassium hydroxide
  D) mercury
  Show Answer
  The correct answer is B .