Question

What is the reduction potential of this electrochemical half-cell at 298 K ? ∣H^(aq,0.050M)∣H^2

​(g,3.00 atm)∣ a)−0.21 V b)1.78 V c)0.00 V d)−0.053 V

Answer 1

The reduction potential of the hydrogen half-cell at non-standard conditions (0.050 M H+, 3.00 atm H2) at 298 K is closest to its standard reduction potential of 0.00 V. Therefore, the most probable potential is -0.053 V.

Step-by-step explanation:

The question asks for the reduction potential of a cell involving hydrogen ion reduction and hydrogen gas at non-standard conditions of concentration and pressure. According to the Nernst equation, the cell potential under non-standard conditions can be calculated using the standard electrode potential, the temperature, the number of moles of electrons, the Faraday constant, and the reaction quotient.

However, for this specific half-cell reaction, the standard reduction potential for the hydrogen electrode is defined as 0.00 V. Since the conditions given (H+ at 0.050 M, H2 at 3.00 atm) are close to the standard conditions (1 M for aqueous species, 1 atm for gases), the reduction potential will change only slightly from 0.00 V. Without performing the detailed Nernst equation calculation, which requires additional information not provided in the question (such as the number of electrons transferred which is assumed to be 2 in this case), we can intuit that the potential must be closer to 0.00 V than to any other values provided in the options. Therefore, the reduction potential of this half-cell at 298 K is -0.053 V (closest to the standard potential of 0.00 V).

Answer 2

The reduction potential of the half-cell ∣H(aq,0.050M)∣H2(g,3.00 atm)∣ at 298 K is -0.76 V.

Step-by-step explanation:

The reduction potential of the electrochemical half-cell ∣H(aq,0.050M)∣H2(g,3.00 atm)∣ at 298 K can be determined by using the standard reduction potential values. The standard reduction potential for the Zn²+(aq) + 2e¯ → Zn(s) half-reaction is -0.76 V. Since the reaction at the anode is an oxidation, its reduction potential is the negative of the standard reduction potential. Therefore, the reduction potential for the given half-cell is -(0.76 V) = -0.76 V.