A voltaic cell is constructed with all the reactants and products in their standard states. Will
this condition hold as the cell operates? Explain.
What is the solubility of calcium fluoride in a buffer solution containing 0.45 M formic
acid and 0.20 M sodium formate?
Given: Ka for formic acid = 1.7 x 10-4
Ka for hydrofluoric acid = 6.8 x 10-4
Ksp for calcium fluoride = 3.4 x 10-11
No, the solutions will not remain at 1 M. At the anode the metal ion will increase and it will decrease at the cathode (assuming of course that it is a M/M^+||M^+/M cell.
I worked this problem for Tina below.
http://www.jiskha.com/display.cgi?id=1417573947
chem 1070?
To understand whether the condition of all reactants and products in their standard states will hold as a voltaic cell operates, we need to consider the changes that occur in the cell.
A voltaic cell is an electrochemical cell that generates electrical energy through a spontaneous chemical reaction. It consists of two half-cells, each containing an electrode immersed in an electrolyte solution. The half-cells are connected by a wire, allowing the flow of electrons, and an ion-permeable membrane or salt bridge completes the circuit.
During operation, oxidation and reduction half-reactions occur at the electrodes. Oxidation takes place at the anode (negative electrode), where the reactant loses electrons, while reduction occurs at the cathode (positive electrode), where the reactant gains electrons. These half-reactions combine to form the overall cell reaction.
As the cell operates, reactions proceed and electrons flow from the anode to the cathode through the external circuit. This electron flow generates the electrical current. Meanwhile, ions move through the electrolyte solutions and the salt bridge to maintain charge balance and complete the chemical reaction.
Due to these reactions, the concentrations of reactants and products will change over time. As reactant molecules are being consumed at the anode and product molecules are being generated at the cathode, the initial condition of all species being in their standard states will no longer hold.
Therefore, once the voltaic cell begins operating, the concentrations of reactants will decrease, and the concentrations of products will increase. However, it is important to note that the standard state conditions refer to the thermodynamic standard state, which is a reference state used to calculate thermodynamic properties. These standard state conditions are typically defined as 1 M concentration for solutions and 1 atm partial pressure for gases.
So, while the reactant and product concentrations will change during operation, the cell can still be designed and analyzed based on the initial standard state conditions. Understanding how these concentrations change over time is essential for predicting the cell's behavior and calculating its performance through methods like the Nernst equation.