Structure 1 · Models of the Particulate Nature of MatterStructure 1 · 物质粒子性模型
The Particulate Nature of Matter物质的粒子性
IB-Style Practice Questions: Structure 1.1 to 1.5IB 风格练习题：覆盖 Structure 1.1 至 1.5
EASYMEDIUMHARDPaper 1Paper 2Paper 3 HLHL
Topics Structure 1.1 to 1.5考点 Structure 1.1 至 1.5HL
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PART I · PAPER 1第一部分 · 第一卷No calculator · multiple choice · 6 marks不可使用计算器 · 选择题 · 6 分
Multiple Choice选择题
Each item carries 1 mark. No calculator, no data booklet. Items tagged HL test content beyond the standard-level syllabus (mass spectrometry, ionization energy from spectral data).每题 1 分。不可使用计算器与数据手册（data booklet）。标记 HL 的题目考查超出标准级别（SL）大纲的内容：质谱法（mass spectrometry）、由光谱数据求电离能。
Q1MEDIUMPaper 11.1 Kinetic Theory[1]
A fixed mass of ice at −10°C is heated at constant (atmospheric) pressure until it becomes steam at 110°C. Which statement correctly describes the average kinetic energy and average particle separation over the whole process?恒定（大气）压强下，将一定质量、−10°C 的冰加热直至变为 110°C 的蒸汽。下列哪一项正确描述了整个过程中粒子的平均动能与平均间距？
(A)Average kinetic energy increases continuously throughout, including during melting and boiling.平均动能在全程持续增大，包括熔化与沸腾期间。
(B)Average kinetic energy increases while the ice warms and while the steam warms above 100°C, but stays constant during melting and boiling; the greatest increase in particle separation happens during boiling.冰升温与蒸汽在 100°C 以上继续升温时平均动能增大，但熔化与沸腾期间保持不变；粒子间距增大最多的阶段发生在沸腾期间。
(C)Average kinetic energy is constant throughout because the pressure is constant.因压强恒定，平均动能全程保持不变。
(D)The greatest increase in average particle separation occurs during melting, not boiling.粒子间距增大最多的阶段发生在熔化而非沸腾期间。
A fixed amount of gas is compressed to very high pressure at low temperature. The measured volume is found to be larger than the ideal gas equation predicts. This deviation is best explained by:将定量气体在低温下压缩至很高压强。测得体积大于理想气体方程的预测值。对此偏差的最佳解释是：
(A)the pressure exerted on the container walls is lower than ideal because of intermolecular attraction.由于分子间吸引力，气体对容器壁施加的压强低于理想值。
(B)the finite volume of the gas molecules themselves becomes significant, leaving less "free" space to compress into.气体分子自身的体积变得不可忽略，可供压缩的"自由"空间因而变小。
(C)the molecules increasingly undergo inelastic collisions, which increases the volume.分子间越来越多地发生非弹性碰撞，从而使体积增大。
(D)the ideal gas equation systematically overestimates pressure at low temperature.理想气体方程在低温下系统性地高估了压强。
The first six successive ionization energies of an element X (MJ mol$^{-1}$) are: 0.90, 1.76, 14.85, 21.0, 25.0, 32.0. To which group of the periodic table does X most likely belong?元素 X 前六级逐级电离能（MJ mol$^{-1}$）为：0.90、1.76、14.85、21.0、25.0、32.0。X 最可能属于周期表中的哪一族？
PART II · PAPER 2第二部分 · 第二卷Calculator + data booklet · structured response · 40 marks可使用计算器与数据手册 · 结构化解答题 · 40 分
Structured Response结构化解答题
Show all working in the space provided. Marks for correct method are awarded even if the final numerical answer is wrong. State units and significant figures appropriately.在指定区域写出全部解题过程。即便最终数值错误，方法正确仍可得分。注意单位与有效数字（significant figures）。
SR 1MEDIUMPaper 2HL1.2 Isotopes + Mass Spectrometry[10]
The mass spectrum of a sample of naturally occurring gallium shows two peaks: at $m/z = 69$ (relative abundance 60.11%) and at $m/z = 71$ (relative abundance 39.89%).某天然镓样品的质谱图显示两个峰：$m/z = 69$（相对丰度 60.11%）与 $m/z = 71$（相对丰度 39.89%）。
(a)State what is meant by the term isotopes.说明同位素（isotope）一词的含义。[1]
(b)Using the mass spectrum data, calculate the relative atomic mass of gallium to 2 decimal places.利用质谱数据，求镓的相对原子质量，保留两位小数。[3]
(c)Explain, in terms of subatomic particles, why $^{69}$Ga and $^{71}$Ga have identical chemical properties but different physical properties (e.g. density).从亚原子粒子的角度解释为何 $^{69}$Ga 与 $^{71}$Ga 化学性质相同但物理性质（如密度）不同。[3]
(d)Ga$^{3+}$ is a common ion in gallium chemistry. Deduce the number of protons, the number of neutrons in the $^{69}$Ga isotope, and the number of electrons in $^{69}$Ga$^{3+}$.Ga$^{3+}$ 是镓化学中常见的离子。求 $^{69}$Ga$^{3+}$ 中质子数、（$^{69}$Ga 同位素中）中子数与电子数。[3]
SR 2MEDIUMPaper 2HL1.3 Electron Config + Spectra + IE[10]
Consider the element vanadium, V (Z = 23).考虑元素钒 V（Z = 23）。
(a)Write the full electron configuration of a ground-state V atom.写出基态 V 原子的完整电子构型。[2]
(b)Write the condensed (noble-gas core) electron configuration of the V$^{3+}$ ion, and state which sublevel loses electrons first when a transition metal forms a cation.写出 V$^{3+}$ 离子的缩写（惰性气体核心）电子构型，并说明过渡金属形成阳离子时哪个亚层先失去电子。[2]
(c)When gaseous V atoms are excited and electrons fall from $n = 4$ to $n = 2$, a line in the emission spectrum is produced. State two pieces of evidence that a line spectrum provides for the existence of discrete, quantized electron energy levels (rather than a continuous range of energies).当气态 V 原子被激发后电子从 $n = 4$ 跃迁至 $n = 2$ 时，会产生一条发射光谱线。说出线状光谱为电子能级离散（量子化）而非连续这一事实提供的两条证据。[2]
(d)HL: The measured frequency of the convergence limit of the first ionization spectral series for a certain element is $5.47 \times 10^{15}~\mathrm{Hz}$. Calculate the first ionization energy in $\mathrm{kJ\,mol^{-1}}$. ($h = 6.63 \times 10^{-34}~\mathrm{J\,s}$, $N_A = 6.02 \times 10^{23}~\mathrm{mol^{-1}}$.)HL：某元素第一电离光谱系汇聚极限的测得频率为 $5.47 \times 10^{15}~\mathrm{Hz}$。求其第一电离能，单位 $\mathrm{kJ\,mol^{-1}}$。（$h = 6.63 \times 10^{-34}~\mathrm{J\,s}$，$N_A = 6.02 \times 10^{23}~\mathrm{mol^{-1}}$。）[3]
(e)State one reason why successive ionization energies of an element always increase.说明为何元素的逐级电离能总是依次增大，给出一个原因。[1]
SR 3HARDPaper 21.4 Formulas + Concentration + Avogadro[10]
A compound containing only carbon, hydrogen, and oxygen has the composition by mass: 54.5% C, 9.1% H, 36.4% O. Its molar mass is $88.0~\mathrm{g\,mol^{-1}}$.某化合物仅含碳、氢、氧，按质量计组成为：54.5% C、9.1% H、36.4% O。其摩尔质量为 $88.0~\mathrm{g\,mol^{-1}}$。
(a)Determine the empirical formula of the compound. Show your working.求该化合物的实验式，写出计算过程。[3]
(b)Hence determine the molecular formula of the compound.由此求出该化合物的分子式。[2]
(c)A $250~\mathrm{cm^3}$ volumetric flask is prepared containing 2.20 g of this compound dissolved in water and made up to the mark. Calculate the concentration of the solution in $\mathrm{mol\,dm^{-3}}$.配制含 2.20 g 该化合物、定容至 $250~\mathrm{cm^3}$ 的容量瓶溶液。求该溶液的浓度，单位 $\mathrm{mol\,dm^{-3}}$。[2]
(d)A $25.0~\mathrm{cm^3}$ portion of this solution is diluted with water to a total volume of $100.0~\mathrm{cm^3}$. State the concentration of the diluted solution.取该溶液 $25.0~\mathrm{cm^3}$，加水稀释至总体积 $100.0~\mathrm{cm^3}$。给出稀释后溶液的浓度。[1]
(e)The compound is vaporized and reacts completely with excess oxygen gas at constant temperature and pressure. Write the balanced equation for its complete combustion, and use Avogadro's law to state the volume ratio of compound vapor to $\mathrm{CO_2}$ produced, explaining why this ratio equals the mole ratio in the equation.该化合物汽化后与过量氧气在恒温恒压下完全反应。写出其完全燃烧的配平方程式，并利用阿伏伽德罗定律给出化合物蒸气与生成的 $\mathrm{CO_2}$ 的体积比，说明为何该比值等于方程中的摩尔比。[2]
SR 4HARDPaper 21.5 Ideal Gas + Real Gas Deviation[10]
A 0.176 g sample of a volatile liquid X is completely vaporized in a gas syringe. At 373 K and 100 kPa, the vapor occupies $62.2~\mathrm{cm^3}$.将 0.176 g 挥发性液体 X 在气体注射器中完全汽化。在 373 K、100 kPa 下，该蒸气占据 $62.2~\mathrm{cm^3}$。
(a)Calculate the amount, in mol, of gas X using the ideal gas equation.利用理想气体方程计算气体 X 的物质的量（mol）。[2]
(b)Hence calculate the molar mass of X.由此计算 X 的摩尔质量。[2]
(c)The same sample of gas is then cooled to 298 K at constant pressure (100 kPa). Use the combined gas law to calculate the new volume.将该气体样品在恒定压强（100 kPa）下冷却至 298 K。利用气体联合定律求新体积。[2]
(d)Substance X is a polar molecule capable of hydrogen bonding. State and explain one reason why the calculation in (c) might not accurately predict the real volume of X at 298 K.物质 X 是能形成氢键的极性分子。说出并解释 (c) 中的计算为何在 298 K 时可能无法准确预测 X 的真实体积，给出一个原因。[2]
(e)Sketch (describe) how the measured molar volume of gas X at 298 K would compare with the ideal-gas prediction as pressure increases from near zero to very high values. Explain your description by referring to the two assumptions of the ideal-gas model that break down at high pressure.描述在 298 K 下，气体 X 的实测摩尔体积随压强从接近零增大到很高值时，与理想气体预测值相比会如何变化。请结合理想气体模型在高压下失效的两条假设解释你的描述。[2]
PART III · PAPER 3 HL第三部分 · 第三卷 HLCalculator + data booklet · data-based · 34 marks可使用计算器与数据手册 · 数据题 · 34 分
Data-Based Questions (HL)数据题（HL）
These questions test the experimental and quantitative skills associated with Structure 1, including its HL extensions (mass spectrometry, ionization energy, real gas behavior). Higher-level students should attempt all parts.本部分考查 Structure 1 相关的实验与定量技能，包括其 HL 拓展内容（质谱法、电离能、真实气体行为）。HL 学生应作答全部小题。
The mass spectrum of naturally occurring rubidium shows two peaks: at $m/z = 85$ (relative abundance 72.17%) and at $m/z = 87$ (relative abundance 27.83%). Rubidium reacts vigorously with water:天然铷的质谱图显示两个峰：$m/z = 85$（相对丰度 72.17%）与 $m/z = 87$（相对丰度 27.83%）。铷与水剧烈反应：
(a)Using the mass spectrum data, calculate the relative atomic mass of rubidium to 2 decimal places.利用质谱数据，求铷的相对原子质量，保留两位小数。[3]
(b)A sample of rubidium metal has a mass of 5.00 g. Using your answer to (a), calculate the amount, in mol, and hence the number of atoms of Rb in the sample.某铷金属样品质量为 5.00 g。利用 (a) 的结果，求该样品中 Rb 的物质的量（mol）及原子数目。[4]
(c)Calculate the volume of $\mathrm{H_2}$ gas, in $\mathrm{cm^3}$, produced at 100 kPa and 298 K from the complete reaction of the 5.00 g sample of rubidium with excess water, using the ideal gas equation.利用理想气体方程，求 5.00 g 铷样品与过量水完全反应后，在 100 kPa、298 K 下生成的 $\mathrm{H_2}$ 气体体积（单位 $\mathrm{cm^3}$）。[4]
(d)Deduce the full electron configuration of Rb (Z = 37) and of Rb$^+$, and explain in terms of electron configuration why Rb loses exactly one electron to form a stable ion.写出 Rb（Z = 37）与 Rb$^+$ 的完整电子构型，并从电子构型角度解释为何 Rb 恰好失去一个电子形成稳定离子。[3]
(e)Successive ionization energy data for rubidium show a very large jump between IE$_1$ and IE$_2$. Explain what this jump indicates about the electron configuration of rubidium, referencing the main energy level from which each electron is removed.铷的逐级电离能数据显示 IE$_1$ 与 IE$_2$ 之间存在非常大的跃升。结合每个电子被移除时所在的主能级，解释该跃升揭示了铷怎样的电子构型信息。[3]
P3-2HARDPaper 3 HLHLMolar Mass Determination + Error Analysis[17]
A student determines the molar mass of a volatile liquid Y. A small volume of liquid Y is injected into a hot gas syringe at 372 K and 101 kPa (atmospheric); once fully vaporized, the volume and mass of vapor are recorded. The experiment is repeated three times:某学生测定挥发性液体 Y 的摩尔质量。将少量液体 Y 注入 372 K、101 kPa（大气压）下的热气体注射器中；完全汽化后记录蒸气的体积与质量。该实验重复三次：
Trial次数
Volume of vapor (cm³)蒸气体积（cm³）
Mass of vapor (g)蒸气质量（g）
1
57.8
0.0865
2
58.0
0.0870
3
58.4
0.0872
(a)Calculate the mean volume and mean mass of vapor from the three trials.求三次实验中蒸气体积与质量的平均值。[2]
(b)Using the mean values, with $T = 372~\mathrm{K}$ and $P = 101~\mathrm{kPa}$, calculate the experimental molar mass of Y.利用平均值，取 $T = 372~\mathrm{K}$、$P = 101~\mathrm{kPa}$，求 Y 的实验摩尔质量。[4]
(c)The accepted molar mass of Y is $46.07~\mathrm{g\,mol^{-1}}$ (ethanol). Calculate the percentage error in the student's experimental value from (b).Y 的公认摩尔质量为 $46.07~\mathrm{g\,mol^{-1}}$（乙醇）。求 (b) 中实验值的百分误差。[2]
(d)Identify two distinct sources of systematic error in this method that would cause the experimental molar mass to be systematically too high, and explain the direction of each effect.指出该方法中两个不同的系统误差来源，二者均会使实验摩尔质量系统性偏高，并解释每种误差影响的方向。[4]
(e)State one modification to the experimental procedure that would reduce random error (improve precision) in the mass measurement, and briefly justify it.提出一项能降低质量测量中随机误差（提高精度）的实验改进方法，并简要说明理由。[2]
(f)Suggest why this method, in which the vapor is measured just above the liquid's boiling point, gives a more accurate molar mass than attempting the measurement at a lower temperature at which some of substance Y remains liquid.解释为何在刚高于液体沸点的温度下测量蒸气，比在较低温度（此时部分 Y 仍为液态）下测量能得到更准确的摩尔质量。[3]