Process of Separating Water into Hydrogen and Oxygen: Electrolysis
To separate water into hydrogen and oxygen, the process of electrolysis is used. Electrolysis involves the use of an electric current to drive a non-spontaneous chemical reaction. Here is a detailed explanation of the process:
1. Set up the electrolysis apparatus:
- A source of direct current (DC) power, such as a battery or power supply, is connected to two electrodes.
- The electrodes are typically made of inert materials like platinum or graphite.
- The electrodes are immersed in a container filled with water, which acts as the electrolyte.
2. Electrolysis occurs:
- When the electric current is turned on, it flows through the water and causes a chemical reaction.
- The positive electrode, called the anode, attracts negatively charged ions (anions), such as hydroxide ions (OH-).
- At the anode, water molecules lose electrons and undergo oxidation, generating oxygen gas (O2).
3. Formation of hydrogen gas:
- The negative electrode, called the cathode, attracts positively charged ions (cations), such as hydrogen ions (H+).
- At the cathode, water molecules gain electrons and undergo reduction, producing hydrogen gas (H2).
- The hydrogen gas bubbles up at the cathode, while the oxygen gas is released at the anode.
4. Collection of the gases:
- The hydrogen and oxygen gases can be collected separately by using gas collection tubes or other appropriate methods.
- The gases can be tested for purity and properties, such as flammability for hydrogen and supporting combustion for oxygen.
5. Overall reaction:
- The overall reaction for the electrolysis of water can be represented as:
2H2O(l) -> 2H2(g) + O2(g)
6. Applications:
- The separated hydrogen and oxygen gases have various practical applications, such as fuel cells, welding, and chemical synthesis.
In summary, the process of separating water into hydrogen and oxygen involves the use of electrolysis, which utilizes an electric current to break down water molecules into their constituent gases.