浓差电池是怎么产生电动势的？它在实际中有什么用途？
How does a concentration cell generate EMF, and what is it used for in practice?
浓差电池两电极材料相同，仅电解质浓度不同，离子从高浓度向低浓度扩散产生电势差。它可用于测量离子浓度、测定溶解度积，也是浓差腐蚀（差异充气腐蚀）的理论基础。
A concentration cell uses identical electrodes but different electrolyte concentrations; ions diffuse from high to low concentration, generating a potential difference. It can measure ion concentrations and solubility products and underlies differential-aeration (concentration) corrosion.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#浓差电池 #离子扩散 #差异充气腐蚀
为什么海水中钢铁比淡水中更容易发生电化学腐蚀？
Why does steel corrode electrochemically faster in seawater than in freshwater?
海水含有大量溶解盐（尤其氯离子），导电性远高于淡水，使腐蚀微电池回路电阻降低、电流增大。氯离子还能破坏金属表面的钝化膜，加速点蚀，因此海水环境腐蚀更为严重。
Seawater contains abundant dissolved salts (especially chloride) and conducts far better than freshwater, lowering the resistance of corrosion microcell circuits and increasing current. Chloride also breaks passive films and induces pitting, so marine corrosion is much more severe.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#电化学腐蚀 #氯离子 #点蚀
塔菲尔方程 Tafel equation 描述了什么关系？过电位在电催化中为什么重要？
What relationship does the Tafel equation describe, and why is overpotential important in electrocatalysis?
塔菲尔方程 η = a + b·log|j| 描述了过电位 η 与电流密度 j 的对数线性关系，反映电化学反应的动力学阻力。过电位是衡量驱动某反应偏离平衡所需额外电压的指标，越小说明催化剂活性越高，对电解水、燃料电池等至关重要。
The Tafel equation η = a + b·log|j| describes the logarithmic relation between overpotential η and current density j, reflecting the kinetic barrier of an electrochemical step. Overpotential measures the extra voltage needed to drive a reaction away from equilibrium; smaller overpotential means higher catalyst activity, critical for water splitting and fuel cells.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#塔菲尔方程 #过电位 #电催化动力学
牺牲阳极的阴极保护法是什么原理？举一个常见应用。
What is the principle of cathodic protection by a sacrificial anode, and give a common application.
牺牲阳极法把更活泼的金属（如锌、镁）连接到被保护钢铁上，活泼金属作为阳极优先被氧化溶解，被保护体成为阴极而免遭腐蚀。常见于船舶船体、地下管道和热水器的镁棒保护。
Sacrificial-anode cathodic protection connects a more active metal (such as zinc or magnesium) to the steel to be protected; the active metal oxidizes and dissolves as the anode, keeping the protected body cathodic and corrosion-free. Common uses include ship hulls, buried pipelines, and magnesium anode rods in water heaters.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#阴极保护 #牺牲阳极 #金属防护
什么是电解精炼铜？电解液中为什么要加入硫酸？
What is electrolytic refining of copper, and why is sulfuric acid added to the electrolyte?
电解精炼以粗铜为阳极、纯铜为阴极，在硫酸铜溶液中通电，阳极铜溶解、纯铜在阴极沉积，杂质落入阳极泥。加入硫酸可提高溶液电导并提供酸性环境，抑制铜离子的水解。
In electrolytic refining, impure copper is the anode and pure copper the cathode in a copper-sulfate bath; copper dissolves at the anode and deposits pure at the cathode while impurities fall as anode slime. Sulfuric acid raises conductivity and keeps the medium acidic to prevent Cu2+ hydrolysis.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#电解精炼 #阴极沉积 #阳极泥
标准电极电势的正负代表什么含义？如何用它判断氧化还原反应方向？
What does the sign of a standard electrode potential mean, and how is it used to predict redox direction?
标准电极电势越正，说明该电对的氧化态越容易被还原（相应的还原态越难被氧化）；越负则相反，还原态越易失电子。把两个半反应组成电池时，电势较高的电对作正极发生还原、较低者作负极发生氧化，电池电动势 E° = E°(正) − E°(负) 为正即该方向反应可自发进行。
A more positive standard electrode potential means the oxidized form is more readily reduced. In a cell, the half-reaction with the higher potential is reduced and the lower one is oxidized; a positive cell EMF E° indicates a spontaneous reaction.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#标准电极电势 #氧化还原反应 #电池电动势
锂离子电池放电时，锂离子在正负极之间如何迁移？正负极材料起什么作用？
During discharge of a lithium-ion battery, how do Li ions migrate between electrodes, and what roles do the electrode materials play?
放电时 Li 从负极（通常为石墨）脱出，经电解液和隔膜嵌入正极（如 LiCoO2 或磷酸铁锂），电子则经外电路做功。负极提供可逆的锂宿主，正极提供高电势的锂嵌入框架，两者电位差决定电池电压。
On discharge, Li deintercalates from the negative electrode (usually graphite), migrates through the electrolyte and separator, and inserts into the positive electrode (e.g., LiCoO2 or LiFePO4), while electrons do work in the external circuit. The anode is a reversible Li host and the cathode a high-potential insertion framework; their potential difference sets the cell voltage.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
《物理化学》(傅献彩) 第五版 下册 第 10 章 ; 另见: J.-M. Tarascon & M. Armand, Nature 2001, 414, 359 (Nature)
J.-M. Tarascon & M. Armand, Nature 2001, 414, 359 (Nature) ; see also: 《物理化学》(傅献彩) 第五版 下册 第 10 章
#锂离子电池 #锂离子迁移 #嵌脱反应