📚 SQA Year 10 Chemistry Formula & Theorem Quick Reference | SQA 十年级化学公式定理速查手册
This quick reference handbook gathers the essential formulas and theorems required for Year 10 SQA Chemistry, helping you master mole calculations, concentration, gas volumes, titration, energetics, and more. Each concept is presented in a clear, structured format so you can revise efficiently and apply the mathematics with confidence.
本速查手册汇总了 SQA 十年级化学所需的关键公式与定理，涵盖摩尔计算、溶液浓度、气体体积、滴定、能量变化等内容。每个概念都以清晰的结构呈现，帮助你高效复习，自信地运用数学工具解决化学问题。
1. The Mole and Molar Mass | 摩尔与摩尔质量
ormula units (Avogadro constant). The mass of one mole of a substance is its molar mass, given in g mol⁻¹, and is numerically equal to the relative formula mass.
摩尔将物质的质量与它所含的微粒数联系起来。1 mol 精确含有 6.02 × 10²³ 个基本单元（阿伏伽德罗常数）。一摩尔物质的质量称为摩尔质量，单位是 g mol⁻¹，数值上等于该物质的相对式量。
Core formula: n = m / M, where n is the amount of substance (mol), m is the mass (g), and M is the molar mass (g mol⁻¹). Rearranged forms are m = n × M and M = m / n.
核心公式：n = m / M，n 为物质的量（mol），m 为质量（g），M 为摩尔质量（g mol⁻¹）。变形公式为 m = n × M 和 M = m / n。
n = m ÷ M
2. Concentration of Solutions | 溶液浓度
Concentration tells us how much solute is dissolved in a given volume of solution. The standard unit is mol dm⁻³, often written as mol l⁻¹. The formula links amount, concentration and volume.
浓度表示在一定体积溶液中溶解了多少溶质。常用单位是 mol dm⁻³（也写作 mol l⁻¹）。公式把物质的量、浓度和溶液体积联系在一起。
n = c × V When volume is given in cm³, convert to dm³ by dividing by 1000: V (dm³) = V (cm³) / 1000.
n = c × V，n 为物质的量（mol），c 为浓度（mol dm⁻³），V 为溶液体积（dm³）。若体积以 cm³ 给出，需除以 1000 换算为 dm³：V (dm³) = V (cm³) / 1000。
c = n / V
3. Molar Volume of Gases | 气体摩尔体积
One mole of any gas occupies the same volume under the same temperature and pressure. At room temperature and pressure (RTP, about 20 °C and 1 atm) the molar volume, Vₘ, is taken as 24 dm³ mol⁻¹. At standard temperature and pressure (STP, 0 °C and 1 atm) the value is 22.4 dm³ mol⁻¹; SQA typically uses RTP values.
在相同温度和压力下，1 mol 任何气体所占的体积相同。在常温常压下（RTP，约 20 °C 和 1 atm），气体摩尔体积 Vₘ 取 24 dm³ mol⁻¹。在标准状况（STP，0 °C 和 1 atm）下则为 22.4 dm³ mol⁻¹；SQA 考试通常采用常温常压数据。
V = n × Vₘ, where V is volume (dm³), n is amount (mol), Vₘ is molar volume (dm³ mol⁻¹). This relationship is used to connect gas volumes with reacting masses in stoichiometry.
V = n × Vₘ，V 为气体体积（dm³），n 为物质的量（mol），Vₘ 为摩尔体积（dm³ mol⁻¹）。此关系可用于化学计量中气体体积与反应质量之间的换算。
n (gas) = V / 24 (at RTP)
4. Percentage Composition and Empirical Formula | 百分比组成与经验式
The percentage by mass of an element in a compound is calculated using the formula: % The mass of the element in one mole equals the number of atoms of that element multiplied by its relative atomic mass, Aᵣ.
化合物中某元素的质量分数计算公式为：质量分数% = (1 mol 化合物中该元素的质量 / 化合物的摩尔质量) × 100。1 mol 中该元素的质量等于该元素原子个数乘以其相对原子质量 Aᵣ。
The empirical formula shows the simplest whole‑number ratio of atoms in a compound. To find it, convert mass or percentage data to moles ( ÷ Aᵣ ), divide each by the smallest number of moles, and then express as the simplest integer ratio.
经验式（最简式）表示化合物中各元素原子的最简整数比。求法：将质量或百分数换算为物质的量（除以 Aᵣ），分别除以其中最小的物质的量，然后化为最简整数比。
%X = (n(X) × Aᵣ(X) / Mᵣ) × 100
5. Balanced Equations and Mass Calculations | 配平方程式与质量计算
ch reactants combine and products are formed. This ratio is the foundation of all reacting‑ es (÷ molar mass), use the mole ratio from the equation, then moles → mass (× molar mass).
配平的化学方程式给出了反应物与生成物之间的物质的量之比。这一比例是所有反应质量计算的基础。一般计算路径是：质量 → 物质的量（÷ 摩尔质量），利用方程式中系数比，再物质的量 → 质量（× 摩尔质量）。
of moles occupy equal volumes. This allows a shortcut: volume ratio = reacting mole ratio.
对于气体，在相同条件下物质的量之比也等于体积之比，因为相同物质的量的气体占有相同体积。由此可以简化：体积比 = 反应系数之比。
Mass → mol → mol → Mass
6. Rate of Reaction | 反应速率
The average rate of a reaction is the change in quantity of a reactant or product divided by the time taken. The quantity can be mass (g), volume of gas (cm³), or concentration (mol dm⁻³). Units are typically g s⁻¹, cm³ s⁻¹, or mol dm⁻³ s⁻¹.
平均反应速率是指反应物或生成物的某种量的变化量除以时间。这个量可以是质量（g）、气体体积（cm³）或浓度（mol dm⁻³）。常见单位有 g s⁻¹、cm³ s⁻¹ 或 mol dm⁻³ s⁻¹。
Average rate = Δ quantity / Δ time. On a graph of quantity against time, the rate at any instant is the gradient of the tangent at that point. A steeper slope means a faster reaction.
平均速率 = Δ 量 / Δ 时间。在“量‑时间”图上，某一瞬间的反应速率等于该点切线的斜率。斜率越大，反应越快。
Rate = (final quantity – initial quantity) / time
7. Titration Calculations | 滴定计算
Titration is used to find the unknown concentration of a solution by reacting it with a standard solution of known concentration. The key is to first calculate the moles of the known reactant, then use the mole ratio from the balanced equation to find the moles of the unknown, and finally calculate its concentration.
滴定法利用已知浓度的标准溶液与未知浓度溶液反应，从而求得未知浓度。关键步骤是先算出已知反应物的物质的量，再由配平方程式的化学计量比求出待测物的物质的量，最后计算其浓度。
For a 1:1 reaction, the relationship simplifies to: c₁V₁ = c₂V₂ me unit (usually dm³). If the ratio is not 1:1, use n₁ / coefficient₁ = n₂ / coefficient₂.
对于系数为 1:1 的反应，可简化为 c₁V₁ = c₂V₂，c₁ 和 V₁ 为一种溶液的浓度和体积，c₂ 和 V₂ 为另一种。所有体积单位须一致（通常用 dm³）。若系数非 1:1，则使用 n₁ / 系数₁ = n₂ / 系数₂ 进行计算。
n(known) = c × V, then n(unknown) via ratio, then c = n/V
8. pH and Hydrogen Ion Concentration | pH 与氢离子浓度
The pH scale measures the acidity or alkalinity of an aqueous solution. pH is defined as the negative logarithm (base 10) of the hydrogen ion concentration: pH = –log₁₀[H⁺]. Thus, a solution with [H⁺] = 1.0 × 10⁻³ mol dm⁻³ has a pH of 3.
pH 标度用于衡量水溶液的酸碱度。pH 的定义是氢离子浓度的负常用对数：pH = –log₁₀[H⁺]。因此，若 [H⁺] = 1.0 × 10⁻³ mol dm⁻³，则 pH = 3。
To convert pH back to hydrogen ion concentration, use: [H⁺] = 10−pH increases by a factor of 10. Pure water has a pH of 7 because [H⁺] = 1.0 × 10⁻⁷ mol dm⁻³.
由 pH 求氢离子浓度时使用：[H⁺] = 10−pH。pH 每降低 1 个单位，[H⁺] 就增大为原来的 10 倍。纯水的 pH 为 7，因为其 [H⁺] = 1.0 × 10⁻⁷ mol dm⁻³。
pH = –log₁₀[H⁺] [H⁺] = 10−pH
9. Enthalpy Change Calculations | 焓变计算
Thermochemical measurements usually start by using a calorimeter to find the heat energy, q, absorbed or released by the water (or solution). The relationship is q = m c ΔT, where m is the mass of the solution (g), c is the specific heat capacity (for water, 4.18 J g⁻¹ °C⁻¹), and ΔT is the temperature change (°C).
量热法通常先用热量计测定水（或溶液）吸收或放出的能量 q。关系式为 q = m c ΔT，m 是溶液的质量（g），c 是比热容（水的比热容为 4.18 J g⁻¹ °C⁻¹），ΔT 是温度变化（°C）。
To find the molar enthalpy change, divide the heat energy by the number of moles of the limiting reactant that reacted: ΔH = –q / n. The negative sign indicates that for exothermic reactions heat is released (ΔH is negative), while endothermic reactions have +q and positive ΔH.
为求得摩尔焓变，需用热量除以反应中限制反应物的物质的量：ΔH = –q / n。负号表示放热反应失去热量（ΔH 为负值），吸热反应则 q 为正值，ΔH 为正。
q = m c ΔT ΔH = –q / n
10. Relative Atomic Mass from Isotopes | 由同位素计算相对原子质量
Many elements exist as a mixture of isotopes. The relative atomic mass, Aᵣ, of an element is the weighted average of the mass numbers of its isotopes, taking into account their percentage abundances. It is a dimensionless number, often given in the periodic table.
许多元素以同位素混合物的形式存在。元素的相对原子质量 Aᵣ 是其同位素质量数按丰度百分比计算出的加权平均值，是一个无量纲数，常列于元素周期表中。
The calculation is: Aᵣ = ( (%₁ × mass number₁) + (%₂ × mass number₂) + ... ) / 100. Remember to use the mass numbers (protons + neutrons), not the atomic numbers. Abundances must add up to 100%.
计算方法：Aᵣ = ( (%₁ × 质量数₁) + (%₂ × 质量数₂) + … ) / 100。切记使用质量数（质子数+中子数），而非原子序数。各同位素丰度之和须为 100%。
Aᵣ = Σ (abundance × mass number) / 100
11. Gas Volume Ratios from Avogadro’s Law | 阿伏伽德罗定律与气体体积比
Avogadro’s law states that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. For reactions involving gases only, the coefficients in the balanced equation can be read directly as volume ratios, provided temperature and pressure remain constant.
阿伏伽德罗定律指出，在相同温度和压力下，相同体积的气体含有相同的分子数。对于只涉及气体的反应，只要温度、压力不变，配平方程式的系数就可以直接解读为体积比。
gen react with one volume of oxygen to produce two volumes of steam. This saves conversion steps when only gas volumes are asked.
例如，反应 2H₂(g) + O₂(g) → 2H₂O(g) 中，两体积氢气与一体积氧气反应生成两体积水蒸气。当题目只问气体体积时，可省去繁琐的换算步骤。
Gas volume ratio = mole ratio (at constant T, P)
12. Summary Table of Common Formulas | 常用公式速查表
This table brings together the most frequently used equations so you can see them side by side. Use it as a one‑page memory aid when working through practice problems.
下表汇总了最常用的公式，便于快速对照。可在做题时作为一页式记忆辅助。
| Formula / 公式 | What it calculates / 用途 |
|---|---|
| n = m / M | Amount from mass and molar mass / 由质量和摩尔质量求物质的量 |
| n = c × V | Amount from concentration and volume / 由浓度和体积求物质的量 |
| n = V (gas) / Vₘ | Amount from gas volume / 由气体体积求物质的量 |
| % by mass = (mass of element / Mᵣ) × 100 | Percentage composition / 质量分数 |
| Rate = Δ quantity / Δ time | Average reaction rate / 平均反应速率 |
| c₁V₁ = c₂V₂ (1:1 titration) | Finding unknown concentration / 求未知浓度 |
| pH = –log₁₀[H⁺] | pH from hydrogen ion concentration / 由氢离子浓度求 pH |
| [H⁺] = 10−pH | H⁺ concentration from pH / 由 pH 求氢离子浓度 |
| q = m c ΔT | Heat energy transferred / 传递的热量 |
| ΔH = –q / n | Molar enthalpy change / 摩尔焓变 |
| Aᵣ = Σ (% × mass number) / 100 | Relative atomic mass from isotopes / 由同位素计算相对原子质量 |
Published by TutorHao | Chemistry Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图