- 14 19 (a) Write the half reactions for a H - O fuel cell. 2 2 Find the theoretical cell voltage at 25°C if PH. = 1.0 ar P b 0.2 = and [H] = 0.5M at both b electrodes. (Real fuel cells operate at temperatures of 60° 1000°C and produce -0.7V.) (b) If the cell is 70% efficient at converting chemical energy into electrical energy, and a stack of cells produces 20 kW at 220 V, how many grams of H, are consumed in an hour? 2 (c) In the US, engines are frequently rated in "horsepower." Use Table 1-4 to convert 20 kW to horsepower. Answer (a) 1.219 V (b) 4.88 h (c) 26.8 horsepower 20. (a) 1.219 V (b) 4.88 g/h (c) 26.8 horsepower

- 14 19 (a) Write the half reactions for a H - O fuel cell. 2 2 Find the theoretical cell voltage at 25°C if PH. = 1.0 ar P b 0.2 = and [H] = 0.5M at both b electrodes. (Real fuel cells operate at temperatures of 60° 1000°C and produce -0.7V.) (b) If the cell is 70% efficient at converting chemical energy into electrical energy, and a stack of cells produces 20 kW at 220 V, how many grams of H, are consumed in an hour? 2 (c) In the US, engines are frequently rated in "horsepower." Use Table 1-4 to convert 20 kW to horsepower. Answer (a) 1.219 V (b) 4.88 h (c) 26.8 horsepower 20. (a) 1.219 V (b) 4.88 g/h (c) 26.8 horsepower

Chemistry: Principles and Reactions

8th Edition

ISBN:9781305079373

Author:William L. Masterton, Cecile N. Hurley

Publisher:William L. Masterton, Cecile N. Hurley

Chapter17: Electrochemistry

Section: Chapter Questions

Problem 108QAP

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