Gastric juice is made up of substances secreted from parietal cells, chief cells, and mucous-secreting cells. The cells secrete HCl, proteolytic enzyme zymogens, mucin, and intrinsic factor. The pH of gastric juice is acidic, between 1-3. If the pH of gastric juice is 2.1, what is the amount of energy (?G) required for the transport of hydrogen ions from a cell (internal pH of 7.4) into the stomach lumen? Assume that the potential difference across the membrane separating the cell and the interior of the stomach is -60.0 mV (inside of cells negative relative to the lumen of the stomach). Assume that the temperature is 37 °C.

The Faraday constant is 96.5 kJ·V-1·mol-1 and the gas constant is 8.314× 10-3 kJ·mol-1·K-1. Express your answer in kJ/mol.