Question

Column I Column II

(A) Maximum potential for

H-electrode at $p{H}_2=1atm$ (P)-0.414 V

(B) Minimum potential for

H-electrode at $p{H}_2=1atm$ (Q) -0.018 V

(C) Potential of H-electrode set

up in 1 M KCl and $p{H}_2=1atm$ (R) -0.827 V

(D)Potential of H-electrode set up

in 1.0 M HCl and $p{H}_2=1atm$ (S) 0.0 V

• A. A-R: B-S:C-P:D-Q
• B. A-R: B-Q:C-R,S:D-P,Q
• C. A-P,Q: B-P,S:C-S:D-P,S
• D. A-P,R: B-Q,S:C-S:D-S

Answer 1

The correct option is A A-R: B-S:C-P:D-Q

To calculate the potential of hydrogen electrodes, values are substituted in the expression $E_{el}=E_{el}^0-\frac{0.0592}{n}log\frac{P^{H2}}{{\left[H^{+}\right]}^2}$ and answer is calculated.
At 1 atm pressure, the maximum potential of hydrogen electrode is -0.827 V and the minimum potential is 0.0 V.
At 1 atm pressure, the hydrogen electrode is set up in 1 M KCl solution. KCl is a salt. The pH of its solution is 7. Hence the potential of hydrogen electrode is -0.414 V.
At 1 atm pressure, the hydrogen electrode is set up in 1 M HCl solution. HCl is a strong acid. The pH of its solution is 1. Hence the potential of hydrogen electrode is -0.018 V.