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 61:

  

  The IUPAC nomenclature of the structure is

  Options:
  A) 3-chloro-3-methylbutane
  B) 2,2,-dichloro-3-methylbutane
  C) 3-methylchlorobutane
  D) 2-chloro-2-methylbutane
  Show Answer
  The correct answer is D .
• Question 62: The purest from of iron which contains only about 0.1% carbon is Options:
  A) pig iron
  B) wrough iron
  C) cast iron
  D) iron pyrite
  Show Answer
  The correct answer is B .
• Question 63:

  H₃PO_4(aq) + H₂O_(l) ↔ H₂PO₄^-_(aq) + H₃O⁺_(aq)

  ΔH = -13kJ at 298K

  In the reaction above, an increase in temperature would

  Options:
  A) slow downthe reverse reaction
  B) have no effect on the reaction
  C) favour the reverse reaction
  D) favour the forward reaction
  Show Answer
  The correct answer is C .
• Question 64:

  Beryllium and Aluminium have similar properties because they

  Options:
  A) are both metals
  B) belong to the same group
  C) belong to the same period
  D) are positioned diagonally to each other
  Show Answer
  The correct answer is D .
• Question 65: The rate of diffusion of a gas Y is twice that of Z If the relative molecular mass of Y is 64 and the two gases diffuse under the same conditions, find the relative molecular mass of Z Options:
  A) 32
  B) 4
  C) 8
  D) 16
  Show Answer
  The correct answer is D .
• Question 66:

  A colored gas that is known to be poisonous and can readily damage the mucous liningof the lungs is?

  Options:
  A) hydrogen sulphide
  B) carbon(ii)oxide
  C) chlorine
  D) sulphur(iv)oxide
  Show Answer
  The correct answer is C .
• Question 67:

  Zn + 2HCL ZnCl${}_2$ + H${}_2$

  What happens to zinc in the above reaction?

  Options:
  A) oxidized
  B) a reactant
  C) reduced
  D) a metal
  Show Answer
  The correct answer is A .
• Question 68:

  When heat is absorbed during a chemical reaction, the reaction is said to be

  Options:
  A) thermodynamic
  B) exothermic
  C) isothermal
  D) endothermic
  Show Answer
  The correct answer is D .
• Question 69: Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI? Options:
  A) All the metals
  B) Mg ,Fe and Cu
  C) Mg, Fe and Pb
  D) Mg and Fe only
  E) Mg only
  Show Answer
  The correct answer is D .
• Question 70:

  What volume of (dm${}^3$) of water will be added to 10dm${}^3$ of 2.0 mol/dm${}^3$ HCL acid solution to give a final solution of 0.5 mol/dm${}^3$?

  Options:
  A) 30
  B) 40
  C) 20
  D) 50
  Show Answer
  The correct answer is B .