We found in Section 7.5 that E=0.2224 V for Pt|H2| HCl|AgCl| Ag at 25^∘ C. Using the value

We found in Section 7.5 that E=0.2224 V for Pt|H2|...

Key Concepts

Electrochemical Cells

Electrochemical cells are devices that convert chemical energy into electrical energy through redox reactions occurring at two different electrodes. They consist of two half-cells where oxidation and reduction processes take place, and the measurable cell potential reflects the energetic difference between these half-reactions.

Relationship Between Cell Potential and Gibbs Free Energy

The cell potential (E°) and the standard Gibbs free energy change (?G°) of a reaction are directly connected by the equation ?G° = -nFE°, where n is the number of electrons transferred and F is Faraday's constant. This relationship allows for the calculation of the thermodynamic favorability of a redox reaction based on the measured electrode potential.

Standard Gibbs Free Energy of Formation

The standard Gibbs free energy of formation (?fG°) of a compound is the change in free energy when one mole of the compound is formed from its elements in their standard states. This value is crucial for determining the overall free energy change of a reaction, especially when combined with other standard free energy changes from involved species.

Application of Thermodynamic Data in Electrochemistry

Thermodynamic data, such as ?fG° values of ions and compounds, are used in conjunction with electrochemical measurements to analyze and predict the energetics of redox reactions. By integrating these data with the relationship between cell potential and free energy change, one can determine unknown free energy values for species involved in electrochemical processes.

Transcript

00:01 So for this problem we are given the value for ksp at 25 degrees celsius from table 2 which is going to be 1 .6 times 10 to the minus 10.

00:21 This is coming from table 16 .2.

00:24 And we are asked to get the value for ksp at 60 degrees celsius.

00:32 For this equation that we need to use is going to be logarithm k2 divided by k1 is equal to delta h0 divided by r times t2 minus t1 divided by t1 times t2.

00:58 And this derivation you can find it in problem 17 .51 of the book.

01:06 So first of all let's identify what are the values that we require.

01:11 We want to find ksp at 60 degrees celsius.

01:14 So just to make the algebra a little bit easier.

01:17 If we transform this and take the exponential on both sides.

01:21 You can realize that k2 is going to be equal to k1 the exponential of delta h0 divided by r.

01:33 This is going to be square brackets t2 minus t1 divided by t1 times t2.

01:41 Parenthesis square brackets.

01:42 So whenever you have a problem like this that we are asked to find k at a different temperature.

01:49 Always use the target temperature as being k2.

01:53 And you are going to do the same as t2.

01:56 So for this scenario t1 is going to be 298 kelvin.