# The following cell was found to have a potential of 0.2897 V:SCEIIMg2+(a = 3.32 * 10^-3M)membrane electrode for Mg^2+(a) When the solution of known magnesium activity was replaced with an unknown solution, the potentialwas found to be 0.2041 V. What was the pMg of this unknown solution?(b) Assuming an uncertainty of 60.002 V in the junction potential, what is the range of Mg21 activitieswithin which the true value might be expected?(c) What is the relative error in [Mg^2+] associated with the uncertainty in Ej?

Question

The following cell was found to have a potential of 0.2897 V:
SCEIIMg2+(a = 3.32 * 10^-3M)membrane electrode for Mg^2+
(a) When the solution of known magnesium activity was replaced with an unknown solution, the potential
was found to be 0.2041 V. What was the pMg of this unknown solution?
(b) Assuming an uncertainty of 60.002 V in the junction potential, what is the range of Mg21 activities
within which the true value might be expected?
(c) What is the relative error in [Mg^2+] associated with the uncertainty in Ej?