(صورة توضيحية فقط)
ال التحليل الكهربائي of water is the decomposition of water (H₂O) into its constituent elements, oxygen (O₂) and hydrogen (H₂), by passing an electric current through it. At the cathode, two water molecules are reduced to form hydrogen gas and hydroxide ions. At the anode, two water molecules are oxidized to form oxygen gas, protons, and electrons.
The decomposition of pure water into hydrogen and oxygen is a thermodynamically unfavorable process, requiring external energy in the form of electricity. Pure water is a poor conductor of electricity, so an electrolyte, such as a small amount of a soluble salt or an acid like sulfuric acid, is typically added to increase conductivity. The overall balanced equation for the reaction is [latex]2H_2O(l) \rightarrow 2H_2(g) + O_2(g)[/latex].
The process occurs in an electrolytic cell. At the negatively charged cathode, a reduction reaction takes place: [latex]2H_2O(l) + 2e^- \rightarrow H_2(g) + 2OH^-(aq)[/latex]. At the positively charged anode, an oxidation reaction occurs: [latex]2H_2O(l) \rightarrow O_2(g) + 4H^+(aq) + 4e^-[/latex]. The production of hydrogen gas at the cathode is exactly twice the volume of oxygen gas produced at the anode, a direct consequence of the stoichiometry of water. This 2:1 volume ratio is a classic demonstration in chemistry classrooms, often performed using a Hofmann voltameter.
يبلغ الحد الأدنى للجهد اللازم لحدوث التحليل الكهربائي، والمعروف بجهد التحلل، 1.23 فولت في الظروف القياسية. ومع ذلك، عمليًا، يلزم جهد أعلى، يُسمى overpotential, is needed to overcome various activation barriers. The efficiency of water electrolysis is a key factor in the viability of a hydrogen-based economy, with significant research focused on developing more effective and cheaper المحفزات for the anode and cathode to reduce the overpotential and energy consumption.
التحليل الكهربائي للماء
(إذا كان التاريخ غير معروف أو غير ذي صلة، على سبيل المثال "ميكانيكا الموائع"، يتم توفير تقدير تقريبي لظهوره الملحوظ)
الصور والتنزيلات بالحجم الكامل متاحة فقط، ومجانية تمامًا، للأعضاء المسجلين.
> تسجيل الدخول <
