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 2241:

  The molar enthalpy change accompanying the removal of an electron from a gas phase atom orion in its ground state is called?

  Options:
  A) Electron gain enthalpy
  B) Ionization enthalpy
  C) Enthalpy change
  D) Enthalpic gas removal
  Show Answer
  The correct answer is B .
• Question 2242:

  

  Use the diagram to answer this question.

  The colour of the fountain water is

  Options:
  A) blue
  B) orange
  C) red
  D) yellow
  Show Answer
  The correct answer is C .
• Question 2243:

  Which one of the following is not a mixture?

  Options:
  A) Air
  B) Mercury
  C) Milk
  D) Cement
  Show Answer
  The correct answer is B .
• Question 2244:

  

  2HCL_(ag) + CaCO_3(ag) → CaCL_2(ag) + H₂O₍₁₎ + CO

  From the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate (IV) as dilute HCL is added to it?

  Options:
  A) L
  B) M
  C) N
  D) P
  Show Answer
  The correct answer is B .
• Question 2245:

  Mg_(s) + 2HCl_(aq) → MgCl_2(aq) + H_2(g)

  From the equation above, the mass of magnesium required to react with 250cm³ of 0.5M HCl is

  [Mg = 24]

  Options:
  A) 0.3g
  B) 1.5g
  C) 2.4g
  D) 3.0g
  Show Answer
  The correct answer is B .
• Question 2246: Which of the following metals is purified commercially by electrolysis? Options:
  A) Zn
  B) Fe
  C) Sn
  D) Cu
  Show Answer
  The correct answer is D .
• Question 2247: Which of these pairs are synthetic and natural macromolecules respectively? Options:
  A) Haemoglobin and nylon, creatine and polyethylene
  B) Nylon and polyethlene, creatine and Haemoglobin
  C) Nylon and creatine, polyethylene and haemoglobin
  D) Polyethylene and creatine, nylon and haemoglobin
  Show Answer
  The correct answer is C .
• Question 2248: In the industrial production of H₂ is removed by (solution) Options:
  A) washing under pressure
  B) drying over phosphorus (V) oxide
  C) passing the mixture to the limewater
  D) using ammonical copper (I) chlorine
  Show Answer
  The correct answer is A .
• Question 2249: A reaction takes places spontaneously if?
  Options:
  A) ∆G = O
  B) ∆S < O and ∆H > O
  C) ∆H < T ∆S
  D) ∆G > O
  Show Answer
  The correct answer is C .
• Question 2250:

  Give the common name for the following compound (CH${}_3$)${}_2$ CH CH${}_2$ -Br

  Options:
  A) Isobutyl bromide
  B) Methyl bromide
  C) propyl bromide
  D) Butyl bromide
  Show Answer
  The correct answer is A .