📚 IB & OCR Chemistry: Formula Handbook | IB & OCR 化学：公式汇总手册
Mastering chemical formulas is the backbone of success in IB and OCR Chemistry assessments. This handbook brings together the essential equations needed for stoichiometry, energetics, kinetics, equilibrium, electrochemistry, and more. Use it as a quick reference to strengthen your problem-solving skills and boost your confidence in both Paper 1 and Paper 2 calculations.
掌握化学公式是 IB 和 OCR 化学考试取得成功的基石。本手册汇集了在化学计量、能量学、动力学、平衡、电化学等方面所需的关键方程式。将它作为快速参考，以增强解题能力，并在卷一和卷二的计算题中提升信心。
1. Mole Concept and Concentration | 摩尔概念与浓度
The mole (n) is the fundamental quantity linking mass and particle number. n = m / M, where m is mass in grams and M is molar mass in g mol⁻¹.
n = m / M
摩尔（n）是联系质量与粒子数的基本量。 n = m / M，其中 m 为质量（克），M 为摩尔质量（克/摩尔）。
Concentration (c) is expressed in mol dm⁻³. For a solution, c = n / V, where V is the volume in dm³.
c = n / V
浓度（c）以 mol dm⁻³ 表示。对于溶液，c = n / V，其中 V 为体积（dm³）。
For gases at standard conditions: IB defines STP as 0°C and 100 kPa, giving a molar volume Vₘ = 22.7 dm³ mol⁻¹. OCR often uses RTP (room temperature and pressure) with Vₘ = 24 dm³ mol⁻¹. n = V / Vₘ.
n = V / Vₘ
对于标准条件下的气体：IB 定义 STP 为 0°C 和 100 kPa，摩尔体积 Vₘ = 22.7 dm³ mol⁻¹。OCR 通常在室温常压 （RTP） 下使用 Vₘ = 24 dm³ mol⁻¹。 n = V / Vₘ。
2. Gas Laws | 气体定律
The ideal gas equation combines pressure, volume, temperature, and amount: pV = nRT. Use p in Pa, V in m³, T in kelvin, and R = 8.31 J mol⁻¹ K⁻¹.
pV = nRT (R = 8.31 J mol⁻¹ K⁻¹)
理想气体状态方程结合了压力、体积、温度和物质的量：pV = nRT。使用 p 单位为 Pa，V 单位为 m³，T 单位为开尔文，R = 8.31 J mol⁻¹ K⁻¹。
When mass and moles are constant, the combined gas law applies: (p₁V₁) / T₁ = (p₂V₂) / T₂.
(p₁V₁) / T₁ = (p₂V₂) / T₂
当质量和物质的量恒定时，适用联合气体定律：(p₁V₁) / T₁ = (p₂V₂) / T₂。
For converting between kPa and Pa: 1 kPa = 1000 Pa. Temperature must always be in kelvin (K = °C + 273).
单位换算：1 kPa = 1000 Pa。温度必须始终使用开尔文（K = °C + 273）。
3. Energetics and Calorimetry | 能量学与量热学
Heat change in a calorimeter is calculated by q = mcΔT, where q is heat energy (J), m is mass (g), c is specific heat capacity (J g⁻¹ K⁻¹), and ΔT is temperature change (K or °C).
q = mcΔT
量热计中的热量变化由 q = mcΔT 计算，其中 q 为热量（J），m 为质量（g），c 为比热容（J g⁻¹ K⁻¹），ΔT 为温度变化（K 或 °C）。
Enthalpy change per mole: ΔH = q / n (at constant pressure), often with a sign for exothermic (–) or endothermic (+). Scaling by 1000 for kJ is common.
ΔH = q / n
每摩尔焓变：ΔH = q / n（恒压条件下），常以放热（–）或吸热（+）标记符号。换算成千焦时除以 1000。
Using bond enthalpies: ΔH ≈ Σ(bond energies broken) – Σ(bond energies formed).
ΔH = ΣE(bonds broken) – ΣE(bonds formed)
利用键焓：ΔH ≈ Σ（断裂键的键能） – Σ（形成键的键能）。
Hess’s law: standard enthalpy change of reaction ΔH° = ΣΔHf°(products) – ΣΔHf°(reactants).
ΔH° = ΣΔHf°(products) – ΣΔHf°(reactants)
赫斯定律：反应的标准焓变 ΔH° = ΣΔHf°（生成物） – ΣΔHf°（反应物）。
4. Kinetics | 动力学
The rate equation for a reaction aA + bB → products is generally: rate = k[A]ᵐ[B]ⁿ, where m and n are orders with respect to A and B, determined experimentally.
rate = k[A]ᵐ[B]ⁿ
反应 aA + bB → 产物的速率方程通常为：rate = k[A]ᵐ[B]ⁿ，其中 m 和 n 分别是相对 A 和 B 的反应级数，由实验确定。
The Arrhenius equation links rate constant k to temperature T: k = A e^(–Eₐ/RT). Its logarithmic form is extremely useful for determining activation energy.
k = A e^(–Eₐ/(RT))
阿伦尼乌斯方程将速率常数 k 与温度 T 关联：k = A e^(–Eₐ/(RT))。其对数形式对于确定活化能极为有用。
Logarithmic form: ln k = ln A – (Eₐ/R)(1/T). A plot of ln k vs 1/T gives a straight line with slope = –Eₐ/R.
ln k = ln A – Eₐ/(RT) or ln k = ln A – (Eₐ/R)(1/T)
对数形式：ln k = ln A – (Eₐ/R)(1/T)。以 ln k 对 1/T 作图得一条直线，斜率为 –Eₐ/R。
5. Chemical Equilibrium | 化学平衡
For a general reversible reaction aA + bB ⇌ cC + dD, the equilibrium constant Kc is written in terms of concentrations (aq and g only). Solids and pure liquids are omitted.
Kc = [C]ᶜ [D]ᵈ / [A]ᵃ [B]ᵇ
对于一般可逆反应 aA + bB ⇌ cC + dD，平衡常数 Kc 以浓度表示（仅适用于水溶液和气体）。固体和纯液体被省略。
For gaseous equilibria, Kp uses partial pressures. Relationship between Kp and Kc: Kp = Kc (RT)^Δn, where Δn = (c+d) – (a+b) moles of gas.
Kp = (P_Cᶜ P_Dᵈ) / (P_Aᵃ P_Bᵇ) and Kp = Kc (RT)^(Δn)
对于气体平衡，Kp 使用分压。Kp 与 Kc 的关系：Kp = Kc (RT)^(Δn)，其中 Δn = (c+d) – (a+b) 气体摩尔数的变化。
6. Acids and Bases | 酸和碱
pH is defined as the negative logarithm of the hydrogen ion concentration: pH = –log[H⁺]. Similarly, pOH = –log[OH⁻] and pH + pOH = 14 at 298 K.
pH = –log[H⁺] and pOH = –log[OH⁻]
pH 定义为氢离子浓度的负对数：pH = –log[H⁺]。类似地，pOH = –log[OH⁻]，在 298 K 时 pH + pOH = 14。
The acid dissociation constant for a weak acid HA: Ka = [H⁺][A⁻] / [HA]. Its logarithmic form: pKa = –log Ka.
Ka = [H⁺][A⁻] / [HA] and pKa = –log Ka
弱酸 HA 的酸解离常数：Ka = [H⁺][A⁻] / [HA]。其对数形式：pKa = –log Ka。
The ionic product of water: Kw = [H⁺][OH⁻] = 1.0 × 10⁻¹⁴ at 298 K. pKw = 14.
Kw = [H⁺][OH⁻] = 1.0 × 10⁻¹⁴ (298 K)
水的离子积：Kw = [H⁺][OH⁻] = 1.0 × 10⁻¹⁴（298 K）。pKw = 14。
The Henderson–Hasselbalch equation for buffer solutions: pH = pKa + log([A⁻]/[HA]).
pH = pKa + log([A⁻] / [HA])
缓冲溶液的亨德森-哈塞尔巴尔赫方程：pH = pKa + log([A⁻]/[HA])。
7. Electrochemistry | 电化学
The relationship between Gibbs free energy and cell potential: ΔG = –nFE, where n = number of electrons transferred, F = Faraday constant (96 500 C mol⁻¹), and E is the cell potential in volts.
ΔG = –nFE (F = 96 500 C mol⁻¹)
吉布斯自由能与电池电势的关系：ΔG = –nFE，其中 n 为转移电子数，F 为法拉第常数（96 500 C mol⁻¹），E 为电池电势（伏特）。
Standard cell potential: E°cell = E°_cathode – E°_anode (reduction potentials).
E°cell = E°_cathode – E°_anode
标准电池电势：E°cell = E°_阴极 – E°_阳极（还原电势）。
The Nernst equation accounts for non-standard conditions: E = E° – (RT/nF) ln Q. At 298 K, this simplifies to E = E° – (0.0592/n) log Q.
E = E° – (RT / nF) ln Q (298 K: E = E° – 0.0592/n × log Q)
能斯特方程用于非标准条件：E = E° – (RT/nF) ln Q。在 298 K 时简化为 E = E° – (0.0592/n) log Q。
8. Thermodynamics: Entropy and Gibbs Free Energy | 热力学：熵与吉布斯自由能
Entropy change of the system: ΔS°_system = ΣS°(products) – ΣS°(reactants). Entropy change of the surroundings: ΔS_surr = –ΔH/T.
ΔS°_sys = ΣS°(products) – ΣS°(reactants) and ΔS_surr = –ΔH / T
系统的熵变：ΔS°_系统 = ΣS°（生成物）– ΣS°（反应物）。环境的熵变：ΔS_环境 = –ΔH/T。
Total entropy change: ΔS_total = ΔS_sys + ΔS_surr. A spontaneous process has ΔS_total > 0.
ΔS_total = ΔS_sys + ΔS_surr
总熵变：ΔS_总 = ΔS_系统 + ΔS_环境。自发过程的 ΔS_总 > 0。
Gibbs free energy: ΔG = ΔH – TΔS. Under standard conditions: ΔG° = –RT ln K, linking thermodynamics with equilibrium.
ΔG = ΔH – TΔS and ΔG° = –RT ln K
吉布斯自由能：ΔG = ΔH – TΔS。在标准条件下：ΔG° = –RT ln K，将热力学与平衡联系起来。
9. Atomic Structure and Spectroscopy | 原子结构与光谱学
The speed of light, wavelength, and frequency: c = λν, where c = 3.00 × 10⁸ m s⁻¹.
c = λν
光速、波长和频率：c = λν，其中 c = 3.00 × 10⁸ m s⁻¹。
Energy of a photon: E = hν or E = hc/λ, using Planck’s constant h = 6.63 × 10⁻³⁴ J s.
E = hν and E = hc / λ
光子能量：E = hν 或 E = hc/λ，普朗克常数 h = 6.63 × 10⁻³⁴ J s。
Energy change between electronic levels: ΔE = hν = |E₁ – E₂|. This is essential for interpreting emission spectra in IB.
电子能级间的能量变化
Published by TutorHao | IB Chemistry Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导