Electrode Potential (Nernst)
Calculate the electrode potential by the Nernst equation at 25 °C, E = E° − (0.0592 ÷ n) × log₁₀(Q), from the standard potential E° (V), the number of electrons exchanged n and the reaction quotient Q (ratio of product to reactant activities). The result, in volts, is the actual electrode potential under non-standard conditions — essential to predict the spontaneity of redox reactions, a metal's tendency to corrode in a given medium and the operation of cells, batteries and electrochemical sensors. Enter the standard potential, the number of electrons and the reaction quotient.
Resultado
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Potencial de eletrodo (equação de Nernst)
O potencial padrão E° de um eletrodo vale em condições muito específicas (atividades unitárias, 25 °C, 1 atm). No mundo real as concentrações são outras, e o potencial muda — quem descreve essa dependência é a equação de Nernst. Na forma prática a 25 °C: E = E° − (0,0592 ÷ n) × log₁₀(Q), onde n é o número de elétrons trocados e Q é o quociente reacional (a razão entre as atividades/concentrações dos produtos e dos reagentes, cada uma elevada ao seu coeficiente). O termo 0,0592 V vem de 2,303·RT/F a 298 K. A leitura física é direta: aumentar a concentração de reagentes (Q menor) torna o potencial mais positivo (reação mais favorável); acumular produtos (Q maior) o torna mais negativo, até o equilíbrio (E = 0 na célula). A equação de Nernst é onipresente: prevê a tensão real de pilhas e baterias conforme se descarregam, é a base de funcionamento dos eletrodos seletivos e do pHmetro (cuja leitura é uma medida de potencial), e em corrosão permite construir os diagramas de Pourbaix e avaliar a tendência de um metal a corroer num meio de dada concentração e pH. Informe o potencial padrão, o número de elétrons e o quociente reacional.
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Electrochemical Equivalent Weight
Calculate the electrochemical equivalent weight, EW = M ÷ n, dividing the element's molar mass M (g/mol) by the number of electrons exchanged n (valence). The result, in g/eq, is the mass associated with transferring one mole of electrons and appears in nearly every electrochemical calculation: Faraday's law, electrochemical corrosion rate, electrodeposition and anode sizing. For divalent iron (Fe²⁺), for example, EW = 55.85 ÷ 2 ≈ 27.9 g/eq. Enter the molar mass and the number of electrons exchanged.
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