The hydrophobic effect is a key driving force for all sorts of biological systems. When a hydrophobic molecule is placed in water, it disrupts the hydrogen bonding of nearby water molecules. Let's consider a simple tetrahedral model of hydrogen bonding to investigate this entropic component of this effect. hydrogen bond oxygen hydrogen a) Depicted above and to the left, is an idealized model of the hydrogen bonding network for a single (central) water molecule. i) For the central water molecule how many possible hydrogen bonding configurations exist? HINT: Above and to the right is one such configuration. The four adjacent water molecules are allowed to adopt any orientation to accommodate the central molecule and are not depicted. ii) Replace one of the four adjacent water molecules with a nonpolar molecule. Now, how many possible hydrogen bonding configurations exist? iii) Calculate the difference in entropy for replacing one of the four adjacent water molecules with a nonpolar molecule. b) If we have a hydrophobic molecule in aqueous solution that makes contact with 25 water molecules, what is the change in molar Gibbs energy for adding this molecule into solution? Assume AH-0 and T- 298 K.

The hydrophobic effect is a key driving force for all sorts of biological systems. When a hydrophobic molecule is placed in water, it disrupts the hydrogen bonding of nearby water molecules. Let's consider a simple tetrahedral model of hydrogen bonding to investigate this entropic component of this effect. hydrogen bond oxygen hydrogen a) Depicted above and to the left, is an idealized model of the hydrogen bonding network for a single (central) water molecule. i) For the central water molecule how many possible hydrogen bonding configurations exist? HINT: Above and to the right is one such configuration. The four adjacent water molecules are allowed to adopt any orientation to accommodate the central molecule and are not depicted. ii) Replace one of the four adjacent water molecules with a nonpolar molecule. Now, how many possible hydrogen bonding configurations exist? iii) Calculate the difference in entropy for replacing one of the four adjacent water molecules with a nonpolar molecule. b) If we have a hydrophobic molecule in aqueous solution that makes contact with 25 water molecules, what is the change in molar Gibbs energy for adding this molecule into solution? Assume AH-0 and T- 298 K.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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