Chemistry 2720, Fall 1996, Test 2

All questions are equally weighted.

Part 1

Answer all questions in this part.

1. Calculate the vapour pressure of sodium metal at .
2. 0.8246g of a newly isolated protein is dissolved in 100.00mL of water. The solution has a density of 1.034g/mL and rises 1.05cm in a capillary tube osmometer at 298K. What is the molar mass of the protein?
3. Suppose that a glucose transporter in a cell is powered by ATP hydrolysis at 310K:

   

   Two glucose molecules are transported into the cell for every ATP hydrolyzed. The ratio of ATP to ADP in the cell is 15 and the concentration of phosphate is 5mmol/L. (Both are held constant by homeostatic mechanisms.) If the extracellular glucose concentration is , what is the maximum glucose concentration which can be obtained in the cell?

4. The solubility product of lead (II) iodide is at 298K. Use Debye-Hückel theory to calculate the solubility of this compound in water.

Part 2

Answer one of the following questions.

1. Derive the differential of G from first principles. Use your differential to relate the derivatives to G to thermodynamic variables.
2. Very few reactions are exactly thermoneutral. Suppose however that you are studying a reaction in which the equilibrium constant only increases by one part in 100000 (i.e. ) when the temperature is raised from to . Write as 1+x and use Taylor's theorem to find an approximation to valid for small x. Use this result to calculate for the reaction.
3. Suppose that you want to make compound C by the gas-phase reaction

   

   but the above reaction produces a very poor yield under normal conditions. How might you try to improve the yield of C? Describe at least two different methods.