How to Change Water to Hydrogen
The process of decomposing water into its component atoms of hydrogen and oxygen in response to an electrical current is called electrolysis. This process will liberate twice as much hydrogen as oxygen since each water molecule (H2O) contains two hydrogen atoms and only one oxygen atom. However, the total amount of each gas produced will be proportional to the total electrical charge passed through the water. This reaction will require an electrolyte as pure water is a poor conductor of electricity.
Instructions
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1
Select a suitable electrolyte. In general, a strong acid or base makes a good electrolyte for the electrolysis of water. Sulfuric acid (H2SO4), potassium hydroxide (KOH) and sodium hydroxide (NaOH) are common choices for the electrolyte.
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2
Mix a small quantity of the electrolyte in a container of water. The concentration of electrolyte is not particularly important for the purposes of a laboratory demonstration as the electrolyte's purpose is simply to allow the water to conduct electricity.
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3
Place two leads from a battery into the electrolytic solution created in Step 2 and observe the bubbles that form around the leads. The bubbles at the positively charged lead (cathode) is hydrogen gas and the bubbles at the negatively charge lead (anode) is oxygen gas.
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4
Use a Hofmann voltameter to perform the electrolysis of water more effectively. This device may be used as an electrolytic cell and consists of three cells. The two side cylinders contain one of the two electrodes and the middle cell contains the electrolytic solution.
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Perform electrolysis in industry. Modern electrolytic cells are more sophisticated versions of the Hofmann voltameter that consist of many cells. They are able to produce hydrogen and oxygen gas of very high purity for applications such as oxyhydrogen torches.
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Tips & Warnings
Don't use table salt ( NaCl) as the electrolyte as this will cause the formation of chlorine gas (Cl2) at the anode.
