A voltaic cell employs the following redox reaction:
Sn^2+(aq)+ Mn(s)--> Sn(s) + Mn^2+(aq)
Calculate the cell potential at 25 under each of the following conditions.
a.)[Sn]= 1.51E-2 M [Mn]= 2.52M
b.)[Sn]= 2.52 [Mn]= 1.51E-2 M
That is 25 degree celsius
Obviously [Sn] can't be anything other than 1.00. You must mean [Sn^+2]. Same for Mn.
The easiest way to handle this is to calculate the half cell potential for each half cell, then add them together.
The reduction potential equation is
Ehalfcell = Eo-(0.0592/n)*log(red/ox)
For Sn that is
Ehalfcell = Eo (look up the potential as a reduction potential), then - (0.0592/2)*log(1/0.0151) = ?? (Note: The 1.00 is the value for Sn solid and 0.0151 is the value for Sn^+2 from the problem.)
Do the same thing for the Mn couple (but do it as a reduction), then reverse the equation, change the sign of the potential, and add the oxidation half to the reduction half. Post your work if you get stuck.
Thank you
To calculate the cell potential for each condition, you need to use the Nernst equation. The Nernst equation relates the cell potential to the concentration of the species involved in the redox reaction. It is given by:
E = E° - (RT/nF) * ln(Q)
Where:
E is the cell potential
E° is the standard cell potential
R is the gas constant (8.314 J/(mol·K))
T is the temperature in Kelvin (25 °C = 298 K)
n is the number of electrons exchanged in the redox reaction
F is Faraday's constant (96485 C/mol)
ln(Q) is the natural logarithm of the reaction quotient
Let's calculate the cell potential for each condition:
a) [Sn] = 1.51E-2 M, [Mn] = 2.52 M
In this case, the reaction quotient Q is calculated as follows:
Q = ([Sn]/[Mn])^(coefficient of Sn) * ([Mn]/[Sn])^(coefficient of Mn)
= (1.51E-2/2.52)^(1) * (2.52/1.51E-2)^(1)
= 5.952 * 166.225
= 991.38
Now, let's substitute the values into the Nernst equation:
E = E° - (RT/nF) * ln(Q)
= E° - (8.314 * 298 / (2 * 96485)) * ln(991.38)
b) [Sn] = 2.52 M, [Mn] = 1.51E-2 M
In this case, the reaction quotient Q is calculated as follows:
Q = ([Sn]/[Mn])^(coefficient of Sn) * ([Mn]/[Sn])^(coefficient of Mn)
= (2.52/1.51E-2)^(1) * (1.51E-2/2.52)^(1)
= 166.225 * 5.952
= 991.38
Now, let's substitute the values into the Nernst equation:
E = E° - (RT/nF) * ln(Q)
= E° - (8.314 * 298 / (2 * 96485)) * ln(991.38)
Please note that you would need to know the standard cell potential, E°, of the given redox reaction to calculate the actual cell potential.