A current of 1 A is passed through 200ml solution of 0.05M .Licl solut...
Overview
In this question, we are required to find out the pH of a 200ml solution of 0.05M LiCl solution after passing a current of 1A for 96.5 seconds.
Calculations
First, we need to calculate the amount of charge that has passed through the solution:
Q = I * t
where I = 1A and t = 96.5s
Therefore, Q = 96.5C
Next, we need to calculate the number of moles of LiCl that have been electrolyzed:
n = Q / F
where F is the Faraday constant, which is 96,485 C/mol
Therefore, n = 0.001 mol
We also need to consider the reaction that takes place during electrolysis:
2H2O(l) → O2(g) + 4H+(aq) + 4e-
From the above reaction, we can see that for every 4 electrons that are transferred, 4 H+ ions are produced. Therefore, the concentration of H+ ions increases during electrolysis.
Now, we can calculate the new concentration of H+ ions:
mol H+ = 4 * n = 0.004 mol
volume of solution = 0.2 L
[H+] = mol H+ / volume of solution
Therefore, [H+] = 0.02 M
Finally, we can calculate the pH of the solution:
pH = -log[H+]
Therefore, pH = 1.7
Conclusion
The pH of the solution at the end of the electrolysis is 1.7. This is because the concentration of H+ ions increases during electrolysis, leading to a decrease in pH.