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Chemistry Past Questions and Answers

Chemistry Questions

Question 131:
JAMB 1979
Which one of these compounds will NOT give an oxygen gas on heating?
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  • A Manganese dioxide
  • B Hydrogen peroxide
  • C Zinc nitrate
  • D Sodium nitrate
  • E Ammonium nitrate
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Question 132:
JAMB 1979
In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because
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  • A It makes bauxite a better conductor of electricity
  • B It makes bauxite melt at a lower temperature
  • C It makes aluminium purer
  • D It prevents aluminium from getting oxidized
  • E It protects the carbon electrodes used in the process
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Question 133:
JAMB 1979
In the redox reaction 2Fe<sup style='font-size: smaller;'>2+</sup> + CI<sub style='font-size: smaller;'>2</sub> → 2Fe <sup style='font-size: smaller;'>3 +</sup> + 2Cl
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  • A Cl<sub style='font-size: smaller;'>2</sub> is reduced because it has lost electrons
  • B Cl<sub style='font-size: smaller;'>2</sub> is reduced because its oxidation number has decreased
  • C Cl<sub style='font-size: smaller;'>2</sub> is reduced because its molecule is change to two ions
  • D Fe<sup style='font-size: smaller;'>2+</sup> is reduced because it has lost electrons
  • E Fe<sup style='font-size: smaller;'>2+</sup> is reduced because it has gained electrons
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Question 134:
JAMB 1979
An anhydride is
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  • A A compound wich has no water of crystallization
  • B An oxide whose solution in water has a PH greater than 7
  • C An oxide whose solution in water has a PH less than 7
  • D An oxide that has hydrogen atoms
  • E An amphoteric oxide
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Question 135:
JAMB 1979
In which of the following reactions is sulphur dioxide acting as an oxidizing agent?
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  • A SO <sub style='font-size: smaller;'>2</sub> + 2HNO<sub style='font-size: smaller;'>3</sub> →H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub> + NO<sub style='font-size: smaller;'>2</sub> + Heat
  • B 2SO<sub style='font-size: smaller;'>2</sub> + 2H<sub style='font-size: smaller;'>2</sub>O + O<sub style='font-size: smaller;'>2</sub>→ 2H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub>
  • C SO<sub style='font-size: smaller;'>2</sub> + 2H<sub style='font-size: smaller;'>2</sub>O + CI<sub style='font-size: smaller;'>2</sub>→ H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub> + 2HCI
  • D SO<sub style='font-size: smaller;'>2</sub> + 2H<sub style='font-size: smaller;'>2</sub>S → 3S + 2H<sub style='font-size: smaller;'>2</sub>O
  • E SO<sub style='font-size: smaller;'>2</sub> + H<sub style='font-size: smaller;'>2</sub>O → H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>3</sub>
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