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The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?
- a)The pH of solution decreases
- b)The pH of solution increases
- c)Cl2 is liberated at cathode
- d)The pH of solution remains the same
Correct answer is option 'B'. Can you explain this answer?
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Most Upvoted Answer
The pH of aqueous KCl solution is 7.0. This solution was electrolysed ...
Explanation:
When KCl is dissolved in water, it ionizes to give K+ and Cl- ions. Since K+ ions do not undergo any reaction in water, the pH of the solution is determined by the hydrolysis of Cl- ions.
Cl- + H2O ⇌ HCl + OH-
In this equilibrium, HCl is a strong acid and dissociates completely to give H+ and Cl- ions. Since the concentration of OH- ions increases in this process, the pH of the solution decreases. Therefore, the initial pH of the KCl solution is less than 7.
During electrolysis, water molecules are also ionized at the electrodes to give H+ and OH- ions. The H+ ions are reduced at the cathode to form H2 gas, while the OH- ions are oxidized at the anode to form O2 gas.
2H+ + 2e- → H2
4OH- → O2 + 2H2O + 4e-
Since H+ ions are removed from the solution, the concentration of OH- ions increases, which causes the pH of the solution to increase. Therefore, option B is the correct answer.
Additionally, Cl2 is not liberated at the cathode because K+ ions are preferentially reduced due to their lower reduction potential. Cl- ions are oxidized at the anode to form Cl2 gas instead.
When KCl is dissolved in water, it ionizes to give K+ and Cl- ions. Since K+ ions do not undergo any reaction in water, the pH of the solution is determined by the hydrolysis of Cl- ions.
Cl- + H2O ⇌ HCl + OH-
In this equilibrium, HCl is a strong acid and dissociates completely to give H+ and Cl- ions. Since the concentration of OH- ions increases in this process, the pH of the solution decreases. Therefore, the initial pH of the KCl solution is less than 7.
During electrolysis, water molecules are also ionized at the electrodes to give H+ and OH- ions. The H+ ions are reduced at the cathode to form H2 gas, while the OH- ions are oxidized at the anode to form O2 gas.
2H+ + 2e- → H2
4OH- → O2 + 2H2O + 4e-
Since H+ ions are removed from the solution, the concentration of OH- ions increases, which causes the pH of the solution to increase. Therefore, option B is the correct answer.
Additionally, Cl2 is not liberated at the cathode because K+ ions are preferentially reduced due to their lower reduction potential. Cl- ions are oxidized at the anode to form Cl2 gas instead.
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Community Answer
The pH of aqueous KCl solution is 7.0. This solution was electrolysed ...
Option B is correct becz during electrolysis, at anode there is oxidation of Cl minus ions (among Cl minus and OH minus present in soln. ) liberating Cl2 while on cathode there is reduction of H plus ions (among k plus & H plus in soln.) liberating H2, leaving OH minus and k+ ions in the soln this OH minus ion is responsible for increasing pH of soln.
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The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer?
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The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer?.
The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The pH of aqueous KCl solution is 7.0. This solution was electrolysed for a few seconds using Pt electrodes. Which of the following is correct?a) The pH of solution decreases b) The pH of solution increases c) Cl2 is liberated at cathode d) The pH of solution remains the same Correct answer is option 'B'. Can you explain this answer?.
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