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Chemistry Past Questions and Answers

Topic: Dilute and concentrated NaCl solutions

Jamb Chemistry Questions - Dilute and concentrated NaCl solutions

Question 6:
The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is?
  • A Sodium
  • B Chlorine
  • C Hydrogen
  • D Sodium hydroxide
  • E Oxygen
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Question 7:
When a solution of silver (l) nitrate is saturated with hydrogen sulphide, a black precipitate forms which is?
  • A H<sub style='font-size: smaller;'>2</sub>S
  • B Ag<sub style='font-size: smaller;'>2</sub>S
  • C PbS
  • D HNO<sub style='font-size: smaller;'>3</sub>
  • E S
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Question 8:
A current of 10.0A was passed for 1 hour through a solution of copper (ll) sulphate between the copper electrodes. Which of the following observation would be correct?
(1 Faraday = 96,500 coulobms) (i) 0.186 mole of copper is dissolved from the anode. (ii) 0.372 mole of copper is deposited on the cathode. (iii) the original Cu2+ ion concentration of the solution remains unchanged. (iv) the original Cu2+ ion concentration of the solution decreases.
  • A I and ii
  • B I and iii
  • C I and iv
  • D Ii and iii
  • E Ii and iv
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Question 9:
How many coulombs of electricity are passed through a solution in which 6.5 amperes are allowed to run for 1.0 hour?
  • A 3.90 x 10<sup style='font-size: smaller;'>2</sup> coulombs
  • B 5.50 x 10<sup style='font-size: smaller;'>3</sup> coulombs
  • C 6.54 x 10<sup style='font-size: smaller;'>3</sup> coulombs
  • D 2.34 x 10<sup style='font-size: smaller;'>4</sup> coulombs
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Question 10:
In the electrolysis of aqueous solution of K2SO 4 in the above cell, which species migrate to the anode?
  • A SO<sup style='font-size: smaller;'>2-</sup>OH <sup style='font-size: smaller;'>-</sup>
  • B K <sup style='font-size: smaller;'>+</sup> and SO <sub style='font-size: smaller;'>4</sub><sup style='font-size: smaller;'>2-</sup>
  • C OH and HO
  • D H<sub style='font-size: smaller;'>3</sub>O <sup style='font-size: smaller;'>+</sup> and K
View Answer & Explanation