Electrolyzed water

A student prepares a sample of hydrogen gas by electrolyzing water at 25°C. She collects 152 mL of H2 at a total pressure of758 mm Hg. Using Appendix 1 to find the vapor pressure of water, calculate... 

V) is actually required to electrolyze water when platinum electrodes are used. Much contemporary research on electrochemical cells involves attempts to reduce the overpotential and hence to increase the efficiency of electrolytic processes. 

When carrying out an electrolysis in solution, we must consider the possibility that other species present might be oxidized or reduced by the electric current. For example, suppose that we want to electrolyze water to produce hydrogen and oxygen. Because pure water does not carry a current, we must add an ionic solute with ions that are less easily oxidized or reduced than water ... 

Koseky S and Isobe S. 2007. Microbial control of fresh produce using electrolyzed water. JARQ 41(4) 273—282. 

An experimental Honda fueling station in the Los Angeles area produces about 1/2-kg of hydrogen per day, about 3.5-kg. It uses 700 square feet of solar panels to produce 6 kilowatts of power to electrolyze water. 

When electrolyzing water, there is another practical difficulty to consider. Pure water is a very poor electrical conductor. To increase the conductivity, an electrolyte that does not interfere in the reaction is added to the water. 

Koseki, S., Yoshida, K., Kamitani, Y., and Itoh, K. (2003). Influence of inoculation method, spot inoculation site, and inoculation size on the efficacy of acidic electrolyzed water against pathogens on lettuce. J. Food Prot. 66, 2010-2016. 

Finally, it is noted that the 02-pumping process can be utilized to carry out other physical measurements and functions. For example, some of the structures described above can be used to control the oxygen content in a gaseous environment(9), electrolyze water(26.), measure gas flow(23) or absolute pressure(27) and realize an ionic transistor (28.). 

One option is to use photovoltaics to produce electricity from solar light and then electrolyze water with it in a separate plant. However, it may turn out to be cheaper to directly photoelectrolyze water using a p-Lype cathode and an n-type anode, each irradiated with solar light, thus producing hydrogen from water directly in one plant. 

Chlorine dioxide is usually not a target of water electrolysis but it may occur when electrolyzing water. This special C102 problem is discussed in Sect. 133.2. 

In the future, as the cost of the fuel cell approaches 50 per kilowatt, the cost of an electrolytic cell to electrolyze water is also expected to approach a low number (about 125/kW). With such low-cost electrolyzer units, the electricity cost of about 0.02 to 0.03/kWh is expected to result in a competitive hydrogen cost. It is also estimated that for a photoelectrochemical method to compete, its cost must approach 0.04 to 0.05/kWh. The order-of-magnitude reductions in cost for both hydrogen processes are similar. 

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