标准电极电势表Standard electrode potentials, E°
标准电极电势 E° 是某电对在标准状态（298 K，溶液浓度 1 mol dm⁻³，气体 100 kPa）下相对于标准氢电极的还原电势。E° 越正，电对中的氧化型越容易得电子，是越强的氧化剂；E° 越负，还原型越容易失电子，是越强的还原剂。表中半反应一律写成还原方向。
The standard electrode potential E° is the reduction potential of a redox couple under standard conditions (298 K, 1 mol dm⁻³ solutions, 100 kPa gases) measured against the standard hydrogen electrode. The more positive E°, the more readily the oxidised form gains electrons, making it a stronger oxidising agent; the more negative E°, the more readily the reduced form loses electrons, making it a stronger reducing agent. Every half-equation is written as a reduction.
使用方法How to use it
电池电动势：E°cell = E°(正极) − E°(负极)。正极是 E° 较正的电对，发生还原；负极 E° 较负，发生氧化。
Cell potential: E°cell = E°(positive electrode) − E°(negative electrode). The couple with the more positive E° is the positive electrode and is reduced; the other is oxidised.
判断反应能否自发：E°cell > 0 时反应在标准状态下可自发进行。实际能否观察到还取决于速率（活化能）和浓度。
Feasibility: a reaction is feasible under standard conditions when E°cell > 0. Whether it is observed also depends on rate (activation energy) and concentration.
与吉布斯自由能的关系：ΔG° = −nFE°cell，F = 96 485 C mol⁻¹，n 为转移的电子数。
Link to Gibbs energy: ΔG° = −nFE°cell, with F = 96 485 C mol⁻¹ and n the number of electrons transferred.
非标准浓度用能斯特方程：E = E° + (0.059/n) lg([氧化型]/[还原型])（298 K）。
For non-standard concentrations use the Nernst equation: E = E° + (0.059/n) log([oxidised]/[reduced]) at 298 K.
半反应乘以系数时 E° 不变：E° 是强度性质，与反应写多少不成比例。
Multiplying a half-equation by a coefficient does not change E°: it is an intensive property.
电池电动势计算器Cell potential calculator
标准还原电势（298 K）Standard reduction potentials (298 K)
图中只标出常用电对，完整数据见右表。Only common couples are drawn; the table lists them all.
| 电对 Couple | 半反应 Half-equation | E° / V | 说明 Notes |
|---|---|---|---|
| F₂ / F⁻ | F₂ + 2e⁻ ⇌ 2F⁻ | +2.87 | 最强的常见氧化剂strongest common oxidising agent |
| S₂O₈²⁻ / SO₄²⁻ | S₂O₈²⁻ + 2e⁻ ⇌ 2SO₄²⁻ | +2.01 | |
| Co³⁺ / Co²⁺ | Co³⁺ + e⁻ ⇌ Co²⁺ | +1.82 | |
| H₂O₂ / H₂O | H₂O₂ + 2H⁺ + 2e⁻ ⇌ 2H₂O | +1.78 | |
| MnO₄⁻ / Mn²⁺ | MnO₄⁻ + 8H⁺ + 5e⁻ ⇌ Mn²⁺ + 4H₂O | +1.51 | 酸性高锰酸钾滴定acidified permanganate titrations |
| PbO₂ / Pb²⁺ | PbO₂ + 4H⁺ + 2e⁻ ⇌ Pb²⁺ + 2H₂O | +1.46 | 铅酸蓄电池正极lead–acid cell positive plate |
| Cl₂ / Cl⁻ | Cl₂ + 2e⁻ ⇌ 2Cl⁻ | +1.36 | |
| Cr₂O₇²⁻ / Cr³⁺ | Cr₂O₇²⁻ + 14H⁺ + 6e⁻ ⇌ 2Cr³⁺ + 7H₂O | +1.33 | 橙色 → 绿色orange → green |
| O₂ / H₂O | O₂ + 4H⁺ + 4e⁻ ⇌ 2H₂O | +1.23 | 酸性溶液acidic solution |
| MnO₂ / Mn²⁺ | MnO₂ + 4H⁺ + 2e⁻ ⇌ Mn²⁺ + 2H₂O | +1.23 | |
| Br₂ / Br⁻ | Br₂ + 2e⁻ ⇌ 2Br⁻ | +1.07 | |
| VO₂⁺ / VO²⁺ | VO₂⁺ + 2H⁺ + e⁻ ⇌ VO²⁺ + H₂O | +1.00 | 钒 +5 → +4，黄 → 蓝vanadium +5 → +4, yellow → blue |
| NO₃⁻ / NO | NO₃⁻ + 4H⁺ + 3e⁻ ⇌ NO + 2H₂O | +0.96 | 稀硝酸dilute nitric acid |
| ClO⁻ / Cl⁻ | ClO⁻ + H₂O + 2e⁻ ⇌ Cl⁻ + 2OH⁻ | +0.81 | 碱性溶液alkaline solution |
| Ag⁺ / Ag | Ag⁺ + e⁻ ⇌ Ag | +0.80 | |
| Fe³⁺ / Fe²⁺ | Fe³⁺ + e⁻ ⇌ Fe²⁺ | +0.77 | |
| O₂ / H₂O₂ | O₂ + 2H⁺ + 2e⁻ ⇌ H₂O₂ | +0.70 | |
| I₂ / I⁻ | I₂ + 2e⁻ ⇌ 2I⁻ | +0.54 | |
| Cu⁺ / Cu | Cu⁺ + e⁻ ⇌ Cu | +0.52 | |
| O₂ / OH⁻ | O₂ + 2H₂O + 4e⁻ ⇌ 4OH⁻ | +0.40 | 碱性溶液alkaline solution |
| VO²⁺ / V³⁺ | VO²⁺ + 2H⁺ + e⁻ ⇌ V³⁺ + H₂O | +0.34 | 钒 +4 → +3，蓝 → 绿vanadium +4 → +3, blue → green |
| Cu²⁺ / Cu | Cu²⁺ + 2e⁻ ⇌ Cu | +0.34 | |
| SO₄²⁻ / SO₂ | SO₄²⁻ + 4H⁺ + 2e⁻ ⇌ SO₂ + 2H₂O | +0.17 | |
| Cu²⁺ / Cu⁺ | Cu²⁺ + e⁻ ⇌ Cu⁺ | +0.15 | |
| Sn⁴⁺ / Sn²⁺ | Sn⁴⁺ + 2e⁻ ⇌ Sn²⁺ | +0.15 | |
| S₄O₆²⁻ / S₂O₃²⁻ | S₄O₆²⁻ + 2e⁻ ⇌ 2S₂O₃²⁻ | +0.09 | 碘量法iodometry |
| H⁺ / H₂ | 2H⁺ + 2e⁻ ⇌ H₂ | 0.00 | 标准氢电极，定义为 0standard hydrogen electrode, defined as 0 |
| Fe³⁺ / Fe | Fe³⁺ + 3e⁻ ⇌ Fe | -0.04 | |
| Pb²⁺ / Pb | Pb²⁺ + 2e⁻ ⇌ Pb | -0.13 | |
| Sn²⁺ / Sn | Sn²⁺ + 2e⁻ ⇌ Sn | -0.14 | |
| Ni²⁺ / Ni | Ni²⁺ + 2e⁻ ⇌ Ni | -0.26 | |
| V³⁺ / V²⁺ | V³⁺ + e⁻ ⇌ V²⁺ | -0.26 | 钒 +3 → +2，绿 → 紫vanadium +3 → +2, green → violet |
| Co²⁺ / Co | Co²⁺ + 2e⁻ ⇌ Co | -0.28 | |
| Cr³⁺ / Cr²⁺ | Cr³⁺ + e⁻ ⇌ Cr²⁺ | -0.41 | |
| Fe²⁺ / Fe | Fe²⁺ + 2e⁻ ⇌ Fe | -0.44 | |
| Cr³⁺ / Cr | Cr³⁺ + 3e⁻ ⇌ Cr | -0.74 | |
| Zn²⁺ / Zn | Zn²⁺ + 2e⁻ ⇌ Zn | -0.76 | |
| H₂O / H₂ | 2H₂O + 2e⁻ ⇌ H₂ + 2OH⁻ | -0.83 | 碱性溶液alkaline solution |
| V²⁺ / V | V²⁺ + 2e⁻ ⇌ V | -1.18 | |
| Mn²⁺ / Mn | Mn²⁺ + 2e⁻ ⇌ Mn | -1.18 | |
| Al³⁺ / Al | Al³⁺ + 3e⁻ ⇌ Al | -1.66 | |
| Mg²⁺ / Mg | Mg²⁺ + 2e⁻ ⇌ Mg | -2.37 | |
| Na⁺ / Na | Na⁺ + e⁻ ⇌ Na | -2.71 | |
| Ca²⁺ / Ca | Ca²⁺ + 2e⁻ ⇌ Ca | -2.87 | |
| Ba²⁺ / Ba | Ba²⁺ + 2e⁻ ⇌ Ba | -2.91 | |
| K⁺ / K | K⁺ + e⁻ ⇌ K | -2.93 | |
| Li⁺ / Li | Li⁺ + e⁻ ⇌ Li | -3.04 | 最强的常见还原剂（Li）Li is the strongest common reducing agent |
数据取自 CRC Handbook of Chemistry and Physics，保留两位小数；不同资料可能相差 0.01–0.03 V。Values from the CRC Handbook of Chemistry and Physics, rounded to 0.01 V; sources can differ by 0.01–0.03 V.