The equilibrium constant of a certain reaction was measured at various temperatures to give the plot shown below.What is $\Delta$S° for the reaction in J/mol . K?

Question

Quizplus · Accepted Answer

From the graph, we can see that lnK is equal to -10000/T plus a constant. The slope of this line is equal to -10000/R, where R is the gas constant. Therefore, we can find the value of the equilibrium constant at any temperature using the equation lnK = -10000/T + C, where C is the constant. We can find the value of C by using the value of lnK at one temperature, for example, 300 K. At 300 K, lnK is equal to 3, so we can write:

3 = -10000/300 + C
C = 3 + 10000/300
C = 33.3

Now we can use this value of C to find lnK at any temperature. For example, at 500 K, we have:

lnK = -10000/500 + 33.3
lnK = 13.3

Therefore, the equilibrium constant at 500 K is:

K = e^13.3 = 5.7 x 10^5

Using this method, we can find the equilibrium constant at any temperature. Now we need to find F1F1F1S1F1F1F10S°, which is equal to -R ln K. Using the value of K at 300 K, we have:

F1F1F1S1F1F1F10S° = -8.314 J/mol K x ln(25) = -50 J/mol F1F1F1S1F1F1F10 K

Therefore, the answer is (C).

The Equilibrium Constant of a Certain Reaction Was Measured at Various