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Saturday, 23 May 2026
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Chemistry Past Questions and Answers

Jamb 1998 Chemistry Questions

Question 16:
If an element X of an atomic number Z and mass number Y is irradiated by an intense concentration of neutrons, the relevant nuclear equation is?
  • A <sup style='font-size: smaller;'>y</sup><sub style='font-size: smaller;'>z</sub>X + <sup style='font-size: smaller;'>1</sup><sub style='font-size: smaller;'>0</sub>n → <sup style='font-size: smaller;'>y - 1</sup><sub style='font-size: smaller;'>z + 1</sub>X
  • B <sup style='font-size: smaller;'>y</sup><sub style='font-size: smaller;'>z</sub>X + <sup style='font-size: smaller;'>1</sup><sub style='font-size: smaller;'>0</sub>n → <sup style='font-size: smaller;'>y + 1</sup><sub style='font-size: smaller;'>z</sub>X
  • C <sup style='font-size: smaller;'>y</sup><sub style='font-size: smaller;'>z</sub>X + <sup style='font-size: smaller;'>1</sup><sub style='font-size: smaller;'>0</sub>n → <sup style='font-size: smaller;'>y</sup><sub style='font-size: smaller;'>z + 1</sub>X
  • D <sup style='font-size: smaller;'>y</sup><sub style='font-size: smaller;'>z</sub>X + <sup style='font-size: smaller;'>1</sup><sub style='font-size: smaller;'>0</sub>n → <sup style='font-size: smaller;'>y + 1</sup><sub style='font-size: smaller;'>z - 1</sub>X
View Answer & Explanation
Question 17:
90.0g of MgCI2 was placed in 50.0cm3 of water to give a saturated solubility of the salt is 8.0 mol dm3 at the same temperature, what is the mass of the salt left undissolved at the given temperature?
(Mg = 24, Cl = 35.5)
  • A 52.0g
  • B 58.5g
  • C 85.5g
  • D 88.5g
View Answer & Explanation
Question 18:
Soap lather is an example of a colloid in which a?
  • A Liquid is dispersed in gas
  • B Solid is dispersed in liquid
  • C Gas is dispersed in liquid
  • D Liquid is despersed in liquid
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Question 19:
The pH of a solution obtained by mixing 100cm3 of a 0.2M solution of NaOH is?
  • A 1.3
  • B 7.0
  • C 9.7
  • D 12.7
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Question 20:
Mg2+(aq) + 2e->(aq) → Mg(s)(volts) = 2.370
Zn2+(aq) + 2e->(aq) → Zn(s)(volts) = -0.763
Cds2+(aq) + 2e->(aq) → Cd(s)(volts) = 0.403
Cu2+(aq) + 2e->(aq) → Cu(s)(volts) = 0.340
In the electrochemical series above, the strongest reducing agents is?
  • A Cu <sub style='font-size: smaller;'>(s)</sub>
  • B Cd<sub style='font-size: smaller;'>(s)</sub>
  • C Znsub>(s)
  • D Mg<sub style='font-size: smaller;'>(s)</sub>
View Answer & Explanation