Unit 5: Logam transisi dan kimia nitrogen organik
Pearson Edexcel · International A-Level · Chemistry Topik 5 11:38 Narasi bahasa Inggris · Subtitle bahasa Inggris + 中文 disematkan langsung
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Track electrons in cells and metal redox cycles.
追踪电池中的电子及金属氧化还原循环。
Track lone pairs in complexes and organic reactions.
追踪配合物与有机反应中的孤对电子。
Use Units 1, 2 and 4 as prerequisites.
以第一、二、四单元为前置知识。
Standard means 298 kelvin, 100 kilopascals gas pressure and 1.00 moles per cubic decimetre solutions.
标准条件为 298 开尔文、100 千帕气体压强以及每立方分米 1.00 摩尔的溶液。
The standard hydrogen electrode defines zero.
标准氢电极定义为零电位。
Use inert platinum when the redox pair has no suitable solid electrode.
当氧化还原电对没有合适的固体电极时,使用惰性铂电极。
Zinc is oxidised at the negative electrode.
锌在负极被氧化。
Copper(II) is reduced at the positive electrode.
铜离子在正极被还原。
Electrons move through the wire; salt-bridge ions complete the circuit.
电子通过导线移动,盐桥中的离子完成电路。
Reduction potentials are +0.80 V and +0.34 V.
还原电位分别为+0.80 V和+0.34 V。
What is spontaneous E°cell?
自发的标准电池电动势是多少?
Pause and justify your choice.
请先暂停,论证你的选择。
B: +0.80 − (+0.34) = +0.46 V.
B + 0.80 − (+0.34) = +0.46 V。
The more positive couple is reduced.
更正电势的偶对发生还原反应。
Do not multiply a voltage when balancing electron numbers.
在平衡电子数时,不要乘以电压。
Positive standard E predicts standard thermodynamic feasibility.
正的标准电极电势预测标准热力学可行性。
A large activation barrier can make the reaction too slow to see.
较大的活化能垒可能导致反应速率过慢而无法观察到。
Non-standard concentrations can change potentials and direction.
非标准浓度可能改变电势和反应方向。
Manganate seven gains five electrons in acid; iron 2 plus loses one.
高锰酸根离子在酸性条件下获得五个电子。
One mole of manganate seven reacts with five moles of iron 2 plus.
亚铁离子失去一个电子。 一摩尔高锰酸根与五摩尔亚铁离子反应。
Use sulfuric acid; the endpoint is a persistent faint pink.
使用硫酸。 终点为持久的淡粉色。
Twenty-two point four zero cubic centimetres of zero point zero two zero zero moles per cubic decimetre titrant contains zero point zero zero zero four four eight moles.
22.40 cm³ 浓度为 0.0200 mol dm⁻³ 的滴定剂含有 0.000448 mol。
The iron two plus amount is zero point zero zero two two four moles, in twenty-five point zero zero cubic centimetres, the concentration is zero point zero eight nine six moles per cubic decimetre.
Fe²⁺ 的物质的量为 0.00224 mol,在 25.00 cm³ 中,其浓度为 0.0896 mol dm⁻³。
Two readings at plus or minus zero point zero five cubic centimetres give plus or minus zero point one zero cubic centimetres worst-case titre uncertainty.
两次读数各为 ±0.05 cm³,最坏情况下的滴定体积不确定度为 ±0.10 cm³。
Iodine plus two thiosulfate ions yields two iodide ions plus tetrathionate.
碘加两个硫代硫酸根离子生成两个碘离子和连四硫酸根离子。
Add starch near pale yellow.
接近淡黄色时加入淀粉。
The blue-black colour disappears at the endpoint.
终点时蓝黑色消失。
Use the oxidant and iodide equation before connecting the original oxidant to the titre.
先用氧化剂与碘离子的方程式,再把原氧化剂与滴定体积联系起来。
Acidic oxygen reduction consumes H plus; alkaline oxygen reduction produces OH minus.
酸性氧还原消耗H⁺;碱性氧还原生成OH⁻。
Both hydrogen cells give two H two plus O two yields two H two O overall.
两种氢电池总反应均为2H₂ + O₂ → 2H₂O。
Fuel production and storage matter; methanol operation also produces CO two.
燃料的生产和储存至关重要;甲醇运行也会产生CO₂。
Transition elements form a stable ion with an incomplete d subshell.
过渡元素能形成具有不完整 d 亚层的稳定离子。
Scandium 3 plus is d zero and zinc 2 plus is d ten; copper 2 plus is d nine.
钪离子(三价)为 d0,锌离子(二价)为 d10;铜离子(二价)为 d9。
Remove 4 s electrons before 3 d electrons in positive-ion formation.
形成阳离子时,先移除 4s 电子,再移除 3d 电子。
Coordination number counts donor atoms, not ligand molecules.
配位数计算的是供体原子,而不是配体分子。
Three bidentate ligands can give six-coordinate octahedral geometry.
三个双齿配体可以形成六配位的八面体几何结构。
Four-coordinate square-planar cisplatin has adjacent chlorides.
四配位的平面正方形顺铂具有相邻的氯离子。
⁺ has which chromium state and coordination number?
配合物离子 ⁺ 中铬的氧化态和配位数是多少?
Pause and justify your choice.
请先暂停,说明你的理由。
B: chromium is +3 because two chloride ions contribute −2.
B:铬为+3价,因为两个氯离子贡献了-2价。
Four oxygen and two chlorine donor atoms give coordination number six.
四个氧和两个氯供体原子使配位数为6。
Colour depends on ligand splitting as well as metal oxidation state.
颜色取决于配体场分裂以及金属的氧化态。
Small NH₃ gives copper hydroxide precipitate through proton transfer.
少量氨通过质子转移生成氢氧化铜沉淀。
Excess NH₃ gives deep blue dissolved ammine complex through ligand exchange.
过量氨通过配体交换生成深蓝色的溶解氨配合物。
Zinc hydroxide also dissolves in excess OH⁻ because it is amphoteric.
氢氧化锌也能溶于过量的氢氧根离子中,因为它是两性的。
Two chromate ions plus two H plus are in equilibrium with dichromate plus water.
两个铬酸根离子加两个氢离子与重铬酸根离子加水之间建立平衡。
Chromium stays at plus 6 while yellow changes towards orange.
铬保持正六价,而颜色由黄色变为橙色。
In acidic vanadium reductions, vanadium five, four, three and two are yellow, blue, green and violet.
在酸性条件下的钒还原中,五价、四价、三价和二价钒分别呈黄色、蓝色、绿色和紫色。
The vanadium five oxide to vanadium four oxide steps sum to two sulfur dioxide plus oxygen yielding two sulfur trioxide.
五氧化二钒到四氧化二钒的各步相加,得到两个二氧化硫加氧气生成两个三氧化硫。
The iron 2 plus to iron 3 plus steps cancel in iodide–peroxodisulfate catalysis.
在碘离子与过二硫酸根的催化中,亚铁离子与铁离子之间的各步相互抵消。
The manganese 2 plus product accelerates the manganate–ethanedioate reaction by autocatalysis.
生成的锰离子通过自催化加速高锰酸根与乙二酸根的反应。
Equal intermediate C–C lengths support delocalisation.
相等的中间碳-碳键长支持离域化。
Hydrogenation is less exothermic than three isolated C=C bonds predict.
氢化反应放出的热量少于三个孤立碳碳双键所预测的值。
Substitution restores the delocalised ring; ordinary addition loses it.
取代反应恢复了离域环;普通的加成反应则破坏了它。
Generate NO₂⁺ using concentrated nitric and sulfuric acids.
使用浓硝酸和浓硫酸制备NO₂⁺。
A ring pair forms the C–N bond.
环上的电子对形成C–N键。
Loss of H⁺ restores ring delocalisation and regenerates the acid catalyst.
失去H⁺后恢复环的离域,并再生酸催化剂。
Benzene bromination uses a halogen carrier; phenol needs none in bromine water.
苯的溴化使用卤素载体;苯酚在溴水中则无需任何试剂。
Friedel–Crafts alkylation uses a halogenoalkane/AlCl₃.
傅-克烷基化使用卤代烷与AlCl3。
Acylation uses an acyl chloride/AlCl₃; sulfonation uses fuming sulfuric acid.
酰基化使用酰氯与AlCl3。 磺化使用发烟硫酸。
Br two plus Fe Br three yields Br plus plus Fe Br four minus in the simple electrophile model.
Br₂ + FeBr₃ → Br⁺ + FeBr₄⁻,在简单亲电试剂模型中。
Ring attack and loss of H plus restore the aromatic system.
环进攻并失去H⁺可恢复芳香体系。
Fe Br four minus plus H plus yields Fe Br three plus H Br regenerates the catalyst.
FeBr₄⁻ + H⁺ → FeBr₃ + HBr,再生催化剂。
C₂H₅Cl/AlCl₃ generates the ethyl electrophile in the simple model.
C₂H₅Cl与AlCl₃在简单模型中生成乙基亲电试剂。
Ring attack, C–H pair return and HCl formation restore the aromatic product and catalyst.
环进攻、C–H对恢复以及HCl的生成共同恢复芳香产物和催化剂。
CH₃CO⁺ bonds to the ring through its carbonyl carbon.
CH3CO+ 通过其羰基碳与环连接。
Phenylethanone retains C=O; AlCl₄⁻ accepts H⁺ to regenerate AlCl₃ and form HCl.
苯乙酮保留 C = O。 AlCl4− 接受 H+ 再生 AlCl3 并生成 HCl。
Alkyl groups generally increase amine basicity relative to ammonia.
烷基通常比氨更能增强胺的碱性。
Phenylamine’s lone pair interacts with the ring, reducing basicity.
苯胺的孤对电子与环发生相互作用,从而降低其碱性。
Amides have nitrogen bonded to a carbonyl and are much less basic.
酰胺中氮原子与羰基相连,因此碱性显著减弱。
Halogenoalkane with excess ethanolic ammonia gives a primary amine with further-substitution limits.
卤代烷与过量乙醇氨反应生成伯胺,且进一步取代受到限制。
Nitrile reduction retains the nitrile carbon.
腈还原可保留腈基碳原子。
Sn/HCl reduces nitrobenzene; alkali liberates free phenylamine from the salt.
锡与盐酸还原硝基苯;碱可从盐中游离出苯胺。
Ethanamine has –CH₂NH₂; ethanamide has –CONH₂.
乙胺含有负CH₂NH₂;乙酰胺含有负CONH₂。
Displayed formulae show every bond; skeletal formulae retain heteroatoms and their hydrogens.
展开式显示所有化学键;骨架式保留杂原子及其氢原子。
Cold nitrous acid makes the diazonium salt.
冷亚硝酸生成重氮盐。
Alkaline phenol then couples to form an azo linkage.
碱性酚随后发生偶联反应,形成偶氮键。
Extended delocalisation allows visible-light absorption.
扩展的离域作用使得可见光吸收成为可能。
Which glycine form predominates in strongly alkaline solution?
在强碱性溶液中,哪种甘氨酸形式占主导地位?
Pause and justify your choice.
请先暂停,并说明你的选择理由。
C: H₂NCH₂COO⁻, with net charge −1.
C:H₂NCH₂COO⁻,净电荷为负一。
The zwitterion has NH₃⁺ and COO⁻, net zero.
两性离子含有NH₃⁺和COO,净电荷为零。
Glycine is achiral because its central carbon has two H atoms.
甘氨酸是非手性的,因为其中心碳原子连接了两个氢原子。
Zero the polarimeter with solvent; use monochromatic plane-polarised light.
用溶剂将旋光仪调零。 使用单色平面偏振光。
Match concentration, path length, temperature and wavelength.
确保浓度、光程长度、温度和波长一致。
Opposite pure alanine enantiomers rotate equally oppositely; glycine and a racemate can both give zero.
纯丙氨酸的对映异构体旋转角度相等但方向相反。 甘氨酸和消旋体均可测得零值。
Nylon-6,6 forms by condensation with backbone amide links.
尼龙-6,6通过缩聚反应形成,主链含有酰胺键。
Poly(propenamide) forms by addition and retains amide side groups.
聚丙烯酰胺通过加成聚合形成,并保留酰胺侧基。
Poly(ethenol) OH groups hydrogen-bond to water, supporting soluble-bag use.
聚乙烯醇的羟基与水形成氢键,使其适用于可溶性袋包装。
Ethylmagnesium bromide plus ethanal then acid gives butan-2-ol.
溴化乙基镁与乙醛反应,再经酸处理,生成丁-2-醇。
With methanal it gives propan-1-ol; with CO₂ then acid it gives propanoic acid.
若与甲醛反应,则生成丙-1-醇。 若与二氧化碳反应,再经酸处理,则生成丙酸。
Water added early destroys the reagent and forms ethane.
若过早加入水,会破坏试剂并生成乙烷。
C 3 H 6 O with a carbonyl, an aldehyde hydrogen and a positive Tollens' test fits propanal.
分子式为C3H6O,含有羰基、醛氢且托伦斯试验呈阳性,符合丙醛的特征。
Propanone fits the formula and the carbonyl but fails the aldehyde evidence.
丙酮虽然符合分子式并含有羰基,但不符合醛的证据。
Check the predicted carbon-13 and proton environments against the remaining data.
请将预测的碳-13和质子环境与剩余数据进行核对。
Reflux retains vapour; distillation collects a volatile product.
回流可保留蒸气;蒸馏收集挥发性产物。
Extraction separates layers; carbonate washes remove acid and release CO₂.
萃取用于分离液层;碳酸盐洗涤可除去酸并释放二氧化碳。
Recrystallise from minimum hot solvent, wash cold and dry before yield/melting range.
重结晶应使用最少量的热溶剂,随后在冷态下洗涤、干燥,最后测定产率或熔点范围。
Use separate samples for metal-ion and organic tests with positive controls.
使用独立的样品进行金属离子和有机测试,并设置阳性对照。
For melting range, dry the solid and heat slowly near the expected temperature.
测定熔点范围时,需干燥固体并在预期温度附近缓慢加热。
For boiling temperature, place the bulb at the side arm and record pressure.
测定沸点时,将温度计球部置于侧管处并记录压力。
2.76 grams of salicylic acid, molar mass 138, gives aspirin, molar mass 180, in a 1 to 1 ratio.
2.76 克水杨酸,摩尔质量为 138,按 1 比 1 的比例生成摩尔质量为 180 的阿司匹林。
The dry mass is 2.52 grams.
干燥后的质量为 2.52 克。
What is the percentage yield?
产率是多少?
Pause and justify your choice.
请暂停,并说明理由。
B. 2.76 over 138 is 0.0200 moles; the theoretical mass is 3.60 grams.
答案 B:2.76 除以 138 等于 0.0200 摩尔;理论质量为 3.60 克。
The yield is 2.52 over 3.60, times 100, which is 70.0 percent.
产率等于 2.52 除以 3.60 再乘以 100,即百分之 70.0。
Wet crystals raise the apparent mass without increasing the amount of aspirin.
湿晶体会增加表观质量,但并未增加阿司匹林的实际含量。