Amembrane at 298 k has an interior concentration of 1mm of na* and an exterior concentration of 20 mm. assume that equilibrium has been reached and the free energy difference is zero. calculate the voltage of the interior relative to the exterior. a. -31 mv b.- 60 mv c.-76 mv d. -94 mv

C. -76 mV

Explanation:

The potential of a cell can be calculated by the Nernst equation:

E = E° - (RT/nF)*lnQ

Where E° is the standard potential, R is the gas constant, T is the temperature, F is the Faraday constant, n is the number of electrons at the redox reaction, and Q is the reaction coefficient (products/reactants).

For T = 298 K, the equation can be modified for:

E = E° - (0.0592/n)*logQ

And

E° = -ΔG°/nF

Where ΔG° is free energy, so E° = 0V.

Because the voltage will be calculated of the interior relative to the exterior, the interior is the reactant, and the exterior is the product. So, Q = [Na⁺]exterior/[Na⁺]interior. 1 electron has been replaced in this reaction, so n = 1.

E = -0.0592*log(20/1)

E = -0.076 V

E = -76 mV

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.