the Cu(No3)2 solution was diluted to 0.001 M. The voltage was measured against standard zinc electrode and found to be 0.89 volts..
1. write the cell reaction.
2. write the line notation for the reaction.
3. Use the nernst equation to calculate what the expected voltage should be, and compare to the measured voltage.
Zn + Cu^2+ ==> Cu + Zn^2+
2. I assume when you say standard Zn electrode you mean (Zn^2+) = 1 M.
Zn|Zn^2+(1M)||Cu^2+(0.001M)|Cu
3.
Ecell = Eocell - (0.05916/n)*log Q
n = 2 for the transfer of 2 electrons.
Q = (Zn^2+)(Cu)/(Cu^2+)(Zn)
Fo that (Zn^2+) = 1M; (Cu)=(Zn) = 1; (Cu^2+) = 0.001.
whats the answer for the nernst equation?
what was the value for this nernst equation?
Another question: How did the change in concentration of the copper ions affect the cell potential? Is this change in agreement (qualitatively) with that which would be predicted by LeChatelier's Principle? explain.
To answer the questions, we need to understand the cell reaction, line notation, and the Nernst equation.
1. Cell Reaction:
The cell reaction is the overall chemical equation that occurs in an electrochemical cell. In this case, the copper(II) nitrate solution (Cu(NO3)2) is being reduced at the cathode (Zinc electrode) in comparison to the standard hydrogen electrode (SHE). The cell reaction can be represented as follows:
Cu(NO3)2 + 2 e^- -> Cu + 2 NO3^-
2. Line Notation:
The line notation describes the arrangement of the different species in an electrochemical cell along with the phase and electrode interfaces. Here is the line notation for the given cell reaction:
Zn(s) | Zn2+(1 M) || Cu2+(0.001 M) | Cu(s)
The "||" in the line notation represents the salt bridge or the interface between the different electrolyte solutions.
3. Nernst Equation:
The Nernst equation relates the cell potential (voltage) of an electrochemical cell to the concentrations of the species involved. It can be represented as follows:
E = E° - (RT / nF) * ln(Q)
Where:
- E is the cell potential (voltage).
- E° is the standard cell potential.
- R is the gas constant (8.314 J/mol·K).
- T is the temperature in Kelvin.
- n is the number of moles of electrons transferred in the balanced cell reaction.
- F is Faraday's constant (96,485 C/mol).
- Q is the reaction quotient, which is the ratio of product concentrations to reactant concentrations raised to their stoichiometric coefficients.
To calculate the expected voltage using the Nernst equation, we need the standard cell potential (E°) and the concentrations of the species involved (Cu2+ and Zn2+).
Now, before we proceed, we need to know the standard cell potential (E°) for the given cell reaction. If it is not provided, we can assume it to be 0.34 V.
Let's assume the standard cell potential (E°) is 0.34 V and proceed with the calculation.
First, calculate the reaction quotient (Q) using the concentrations of Cu2+ and Zn2+:
Q = [Cu2+] / [Zn2+]
Given that the Cu(NO3)2 was diluted to 0.001 M, the concentration of Cu2+ is also 0.001 M.
Substituting the values into the Nernst equation:
E = E° - (0.0592 / n) * log10(Q)
Assuming n = 2 (as 2 electrons are involved in the balanced reaction), we can substitute the values:
E = 0.34 V - (0.0592 / 2) * log10(0.001 / [Zn2+])
Now, to compare the expected voltage to the measured voltage, we need the concentration of Zn2+ and the measured voltage. However, this information is not provided in the question. Without that information, we cannot determine the expected voltage or make a direct comparison.
Please provide the concentration of Zn2+ and the measured voltage, and I'll be able to provide a more accurate comparison for you.