Final answer:
The Ksp for Hg2Br2 at 25°C is calculated using the given potential of the galvanic cell and the Nernst equation, resulting in an approximate Ksp value of 3×10^-21 with one significant figure.
Step-by-step explanation:
To calculate the solubility product (Ksp) of Hg2Br2 using the given potential of the galvanic cell, we can use the Nernst equation. At 25°C, the Nernst equation when solving for Ksp can be simplified to the form Ecell = -0.0591 V log Ksp. Rearranging this equation to solve for Ksp gives us:
log Ksp = -Ecell / 0.0591 V
Ksp = 10^(log Ksp)
Plugging in the given cell potential (1.214 V), we proceed with the calculation:
log Ksp = -1.214 V / 0.0591 V = -20.53
Ksp = 10-20.53
Since the question asks for an answer with one significant figure, Ksp would be approximately 3×10-21.
Note that the simplification of the Nernst equation is possible because at standard temperature (25°C), the constants involved can be factored into the equation to yield the -0.0591 V/log Ksp relationship used here.