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Chemistry Past Questions and Answers

Jamb 1999 Chemistry Questions

Question 26:
RS(aq) + HF(aq) → RF(s) + HS(aq)
ΔH = -65.7 kj mol(-1).
From the equation above, it can be deduced that
  • A The heat content of the reactants is lower than that of the products
  • B The heat content of the reactants is higher than that of the products
  • C The reaction is slow
  • D A large amount of heat is absorbed
View Answer & Explanation
Question 27:
Which of the following statement is true of the electrochemical series?
  • A Electropositivity of metals increase down the series
  • B Electropositivity of non-metals decrease down the series
  • C Electronegativity of non-metals decrease down the series
  • D Electropositivity of metals decreases down the series
View Answer & Explanation
Question 28:
The gas that will form a white precipitate with acidified silver trioxonitrate (v) is
  • A NH<sub style='font-size: smaller;'>3</sub>
  • B SO<sub style='font-size: smaller;'>2</sub>
  • C CO<sub style='font-size: smaller;'>2</sub>
  • D HCL
View Answer & Explanation
Question 29:
Chlorine, bromine and iodine resemble one another in that they
  • A Dissolve in alkalis
  • B React violently with hydorgen without heating
  • C Are liquids
  • D Displace one another from solutiions of their salts
View Answer & Explanation
Question 30:
The salt that reacts with dilute hydrochloric acid to produce a pungent smelling gas which decolourizes acidified purple potassium tetraoxomanganate (VII) solution is
  • A Na<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub>
  • B Na<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>3</sub>
  • C Na<sub style='font-size: smaller;'>2</sub>S
  • D Na<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub>
View Answer & Explanation