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 131: A metal that can be extracted from cassitertite is Options:
  A) cacium
  B) magnesium
  C) tin
  D) copper
  Show Answer
  The correct answer is C .
• Question 132:

  

  From the diagram above, an ideal can be represented by

  Options:
  A) M
  B) N
  C) K
  D) L
  Show Answer
  The correct answer is B .
• Question 133: If the relative molecular mass of an element is not a whole number, it can be deduced that the element is Options:
  A) Naturally radioactive
  B) abundant in nature
  C) a transition metal
  D) an isotopic mixture
  Show Answer
  The correct answer is D .
• Question 134:

  

  The diagram above shows the reaction path of an exothermic reaction. The heat of reaction is represented by

  Options:
  A) l
  B) ll
  C) lll
  D) lV
  Show Answer
  The correct answer is D .
• Question 135: A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is? Options:
  A) sulphur (ii) oxide
  B) hydrogen sulphide
  C) sulphide (lV) oxide
  D) hydrogen chloride
  Show Answer
  The correct answer is A .
• Question 136:

  The following are isoelectronic ions except

  Options:
  A) Na${}^{+}$
  B) Mg${}^{2+}$
  C) Si${}^{2+}$
  D) O${}^{2+}$
  Show Answer
  The correct answer is C .
• Question 137:

  ZnO_(s) + CO_(g) → Zn_(s) + CO_2(g)

  In the reaction above, Zinc has been

  Options:
  A) decomposed
  B) displaced
  C) oxidized
  D) reduced
  Show Answer
  The correct answer is D .
• Question 138: How many moles of HCl will be required to react with potassium heptaoxodichromate (VI) to produce 3 moles of chlorine? Options:
  A) 14
  B) 12
  C) 11
  D) 10
  Show Answer
  The correct answer is A .
• Question 139: Which of the following salts will turn blue litmus red? Options:
  A) Sodium tetrahydroxozincate (ll)
  B) Potassium hydrogentetraoxosulphate (lV)
  C) Sodium trioxocarbonate (lV)
  D) Zinc chloride hydroxide
  Show Answer
  The correct answer is B .
• Question 140:

  The solubility of the solids that dissolves in a given solvent with the liberation of heat will

  Options:
  A) increase with an increase in temperature
  B) decrease with an increase in temperature
  C) decrease with a decrease in temperature
  D) not be affected by changes in temperature
  Show Answer
  The correct answer is A .