Question

In a galvanic cell with a cathode containing 1M copper sulfate and an anode with 0.001M zinc sulfate, the EMF is recorded at different temperatures, and the relationship is modeled by the equation EMF = 0.0003T + 1.1 (rearranged Nernst equation). The observed increase in EMF with temperature can be explained by:

a.Changes in the temperature directly affect the resistance of the galvanic cell, following Ohm's law.
b.The Nernst equation inherently accounts for the temperature dependence of electrochemical reactions.
c.As temperature increases, the mobility of ions in the solution decreases, leading to a rise in EMF.
d.The increase in temperature accelerates the rate of electron transfer between the electrodes, resulting in higher EMF.

Answer 1

The increase in EMF with increases in temperature for a galvanic cell is due to the inherent temperature dependence in the Nernst equation, which governs the cell voltage. Option d

Step-by-step explanation:

The observed increase in EMF with temperature in a galvanic cell, modeled by the equation EMF = 0.0003T + 1.1, can be explained by the fact that the Nernst equation inherently accounts for the temperature dependence of electrochemical reactions.

The Nernst equation demonstrates that cell voltage varies as the reaction progresses and the concentrations of the dissolved ions change, directly incorporating the temperature variable. As temperature increases, the reaction quotient (Q) is affected due to changes in ion concentration, which in turn affects the EMF based on Nernst equation modelling.

This is not solely due to the changes in resistance or acceleration of electron transfer, but rather due to the direct inclusion of temperature within the Nernst equation itself, which governs the behavior of the cell voltage. Option d