CO₂ 加氢制甲醇算“负碳”吗？
Is CO₂-to-methanol 'carbon-negative'?
CO₂ 与 H₂ 在 Cu/ZnO 催化下合成甲醇（CH₃OH）；若氢气来自可再生电力，则成为碳循环闭环的关键一环。
CO₂ and H₂ synthesize methanol (CH₃OH) over Cu/ZnO; if the H₂ comes from renewable power, it becomes a key step in closing the carbon loop.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#CO2 #甲醇 #碳循环
绿色化学中溶剂选择要考虑哪些因素？
What factors guide solvent selection in green chemistry?
应优先选无毒、低挥发、可生物降解、来自生物质的溶剂，并避免卤代烃与一类/二类有机溶剂。常采用水、乙醇、超临界 CO₂ 或离子液体，并以溶剂回收率与 E-因子评估整体影响。
Prefer non-toxic, low-volatility, biodegradable, biomass-derived solvents and avoid halogenated or Class 1/2 organic solvents. Water, ethanol, supercritical CO₂, or ionic liquids are favored, with recovery rate and E-factor assessing overall impact.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#溶剂 #毒性 #超临界CO₂
E-因子（环境因子）如何量化化工过程的环境负担？
How does the E-factor quantify the environmental burden of a chemical process?
E-因子 = 废弃物总质量 ÷ 目标产物质量，数值越低越“绿色”。精细化工常高达 25–100，而大宗化工可低于 1，因为多步合成与纯化累积大量溶剂与副产物废物流。
E-factor = total waste mass ÷ product mass; lower is greener. Fine chemicals often reach 25–100 while bulk chemicals can be below 1, because multi-step synthesis and purification accumulate large solvent and byproduct waste streams.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#E因子 #废物 #化工
为什么侯德榜能同时造出纯碱和氮肥？
Why could Hou Debang produce both soda ash and nitrogen fertilizer at once?
侯氏联合制碱法（1943）把氨碱法与合成氨结合：用氨、二氧化碳和食盐制得纯碱，副产氯化铵作氮肥，无废液排放，打破国外垄断。
Hou Debang's combined soda process (1943) couples ammonia-soda with synthetic ammonia: NaCl + NH3 + CO2 yields Na2CO3 and byproduct NH4Cl (nitrogen fertilizer) with no waste liquor, breaking foreign monopolies.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#侯氏制碱 #纯碱 #联合制碱
除了电解，还能怎么分解水制氢？
Besides electrolysis, how else can water be split for hydrogen?
可用高温热化学循环(如硫-碘循环)或聚焦太阳能提供反应热，分步把水分解，避免全程消耗电能。
High-temperature thermochemical cycles (e.g., sulfur–iodine) or concentrated solar heat can split water in steps, avoiding all-electric energy input.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#热化学 #分解水 #制氢
离子液体蒸气压几乎为零，因此常被誉为绿色溶剂，这一称号有哪些依据，又存在哪些争议？
Ionic liquids have an almost undetectably low vapor pressure and are often hailed as green solvents - what supports that reputation, and what controversies cloud it?
依据是阴阳离子间的强静电作用把蒸气压压到检测极限以下，使用环节几乎零挥发性有机物排放，离子组合可像搭积木一样按目标性质定制，并能蒸馏回收多次循环。争议集中在全生命周期视角：部分咪唑类离子液体对水生生物毒性高且难降解，六氟磷酸根遇湿可能水解生成氢氟酸，合成与纯化耗能耗时，一旦缺乏配套回收体系，其整体环境足迹未必优于常规溶剂，绿色标签须逐例审视。
The case rests on the strong Coulomb attraction between paired ions pushing vapor pressure below detection, essentially zero volatile organic emissions during use, modular design of cation-anion combinations for targeted properties, and repeated recovery through distillation. Controversy centers on the lifecycle view: several imidazolium systems show high aquatic toxicity and poor biodegradability, hexafluorophosphate anions can hydrolyze toward hydrofluoric acid on contact with moisture, and synthesis plus purification consume energy and time, so without robust recycling the net footprint need not beat conventional solvents.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
R. D. Rogers、K. R. Seddon《Ionic liquids—solvents of the future?》，Science，2003年，第302卷，792页
R. D. Rogers & K. R. Seddon, Science, 2003, 302, 792 (DOI: 10.1126/science.1090313)
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1126/science.1090313：Ionic Liquids--Solve
#离子液体 #蒸气压 #生命周期评价
可再生原料在绿色化学中的意义是什么？
What is the significance of renewable feedstocks in green chemistry?
用生物质、CO₂、植物油脂等可再生资源替代石油等枯竭性原料，可降低碳足迹并减少对不可再生资源的依赖。例如生物基乙醇、聚乳酸（PLA）源自玉米淀粉而非化石燃料。
Using biomass, CO₂, or plant oils instead of depleting petrochemical feedstocks lowers the carbon footprint and reduces reliance on finite resources—e.g., bio-ethanol and polylactic acid (PLA) from corn starch rather than fossil fuels.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#可再生 #生物质 #碳足迹
绿色化学的十二条原则包含哪些核心思想？
What core ideas are in the twelve principles of green chemistry?
核心包括：预防废弃物优于末端治理、原子经济性最大化、使用低毒合成方法、设计可降解产品、使用可再生原料、避免不必要的保护与衍生、催化优于化学计量试剂、设计节能过程等。它们指导从源头减少环境与健康危害。
Core ideas: prevent waste rather than treat it, maximize atom economy, use low-toxicity methods, design degradable products, use renewable feedstocks, avoid unnecessary protection/derivatization, favor catalysis over stoichiometric reagents, and design energy-efficient processes. They aim to reduce hazard at the source.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#绿色化学 #原则 #可持续性
原子经济性如何衡量反应的“绿色”程度？
How does atom economy measure how 'green' a reaction is?
原子经济性 =（目标产物摩尔质量 ÷ 所有反应物摩尔质量之和）×100%，越高表示进入产物的原子比例越大、副产物越少。它与产率不同：高收率但低原子经济性仍产生大量废物。
Atom economy = (molar mass of desired product ÷ sum of reactant molar masses) ×100%; higher means more atoms end up in the product and less waste. Unlike yield, a high-yield but low-atom-economy reaction still generates much waste.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#原子经济性 #产率 #废物
绿色化学中的“原子经济性”是如何定义的？与传统产率和Sheldon提出的E因子相比，这三种指标在衡量一个合成过程的环境友好程度时各有何侧重？
How is "atom economy" defined in green chemistry? Compared with conventional chemical yield and with Sheldon's E-factor, what aspect of environmental performance does each of these three metrics emphasize?
原子经济性等于目标产物的摩尔质量除以全部反应物摩尔质量之和再乘100%，由Trost于1991年提出，衡量反应物原子最终进入目标产物的比例。产率只反映转化是否充分，不体现副产物造成的浪费；原子经济性则在分子设计阶段就评估原料利用效率。E因子统计每千克产品伴随产生的废弃物总量（含溶剂），反映工艺层面的实际排放，两者互补。
Atom economy is the molar mass of the desired product divided by the sum of the molar masses of all reactants, expressed as a percentage; proposed by Trost in 1991, it measures what fraction of the reactant mass ends up in the target molecule. Yield only reflects how far conversion proceeds, ignoring waste locked up in by-products, whereas atom economy assesses raw-material efficiency already at the molecular-design stage. The E-factor instead tallies the mass of waste produced per unit mass of product, solvents included, capturing process-level emissions. The two views complement each other.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
B. M. Trost，《原子经济性——寻求合成效率》，Science（《科学》）周刊，1991年，第254卷，1471–1473页。
B. M. Trost, "The atom economy - a search for synthetic efficiency", Science, vol. 254, pp. 1471-1473, 1991.
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1126/science.1962206：The Atom Economy—A S
#绿色化学 #原子经济性 #E因子
不含任何化学物质的广告语为什么一定是假的?
Why is any ad claiming contains no chemicals automatically false?
因为万物皆由化学物质构成:水是一氧化二氢,氧气是双原子分子,你身体里跑着成千上万种化合物。化学物质不等于有害,剂量和形态才决定安全性。这类广告玩的是偷换概念,利用对化学的恐惧营销。学会看成分表和理解剂量,比记住恐吓词有用得多——这正是化学素养的意义。
Everything is chemicals: water is dihydrogen monoxide, oxygen a diatomic gas, your body runs thousands of compounds. Chemical never equals harmful — dose and form decide safety. Such ads trade on word-swaps and chemophobia. Reading ingredient lists and understanding dose beats memorizing scare words — that is chemistry literacy.
难度 进阶 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《十万个为什么》第六版化学分册,少年儿童出版社,2013
Ten Thousand Whys: Chemistry volume, 6th ed., Juvenile and Children Publishing House, 2013
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-7-5324-9328-9 · 核验依据 2 ISBN 9787532493289
#化学素养 #剂量决定毒性 #广告话术
“绿色化学”与“可持续化学”有什么区别？
What is the difference between 'green chemistry' and 'sustainable chemistry'?
绿色化学侧重化学反应与工艺本身的环境无害化（原子经济、低毒、节能）；可持续化学范围更广，还包括经济可行、社会公平与全生命周期影响，是更宏观的发展目标。
Green chemistry focuses on making reactions and processes intrinsically benign (atom economy, low toxicity, energy efficiency); sustainable chemistry is broader, also covering economic viability, social equity, and full life-cycle impact as a macro goal.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#绿色 #可持续 #生命周期
为什么绿色化学强调产品可降解？
Why does green chemistry emphasize degradability of products?
设计为在使用后能被微生物或环境分解为无害物质，可避免持久性污染（如某些塑料、含氯有机物在环境中累积）。这与“末端治理”不同，是从分子设计阶段预防危害。
Designing products to break down into harmless substances after use avoids persistent pollution (e.g., accumulated plastics or chlorinated organics). Unlike end-of-pipe treatment, it prevents harm at the molecular-design stage.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#可降解 #污染 #设计
超临界CO2凭什么成为咖啡脱咖啡因和天然产物萃取中的明星绿色溶剂？
What makes supercritical carbon dioxide the star green solvent for decaffeinating coffee and extracting natural products?
因为它把液体的溶解力和气体的传质优点集于一身，而且本质安全、极易分离。CO2超过31.1摄氏度、7.38兆帕即进入超临界态，密度接近液体带来可观的溶解能力，黏度低、扩散快令传质高效；调节压力或温度即可连续改变密度，从而精细调谐溶剂强度与选择性，降压后溶质自动析出、CO2密闭循环回用。它无毒、不可燃、廉价且无任何残留，成功替代了原有的二氯甲烷脱咖工艺。
Because it merges liquid-like solvency with gas-like mass transfer while staying intrinsically safe and easy to separate. Beyond 31.1 degrees Celsius and 7.38 MPa carbon dioxide turns supercritical: near-liquid density supplies substantial dissolving power, and low viscosity with fast diffusion accelerates extraction, while modest changes of pressure or temperature shift the density and thereby tune solvent strength and selectivity; depressurization simply precipitates the solute and sends CO2 back around the closed loop. Nontoxic, nonflammable, cheap and residue-free, it displaced the earlier dichloromethane decaffeination process.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
M. A. McHugh、V. J. Krukonis《Supercritical Fluid Extraction: Principles and Practice》第2版，Butterworth-Heinemann，1994年
M. A. McHugh & V. J. Krukonis, Supercritical Fluid Extraction: Principles and Practice, 2nd ed., Butterworth-Heinemann, 1994
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-0-7506-9244-1 (1994, Butterworth)
#超临界二氧化碳 #绿色溶剂 #超临界流体萃取
为什么有“绿氢”“灰氢”之分？
Why do we distinguish ‘green’ and ‘grey’ hydrogen?
用可再生能源电解水得到的氢叫绿氢；用天然气重整制氢却排放CO2的叫灰氢。颜色代表碳足迹的大小。
Hydrogen from renewable-powered electrolysis is ‘green’; from methane reforming that emits CO2 is ‘grey’. The color signals the carbon footprint.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#绿氢 #灰氢 #碳足迹
催化在绿色化学中为什么重要？
Why is catalysis important in green chemistry?
催化剂以少量反复使用，降低反应温度和活化能、减少能耗与副产物，并常避免化学计量试剂产生大量废弃物，因此被列为绿色化学原则之一。
Catalysts are used in small amounts and reused, lowering temperature and activation energy, cutting energy use and byproducts, and often avoiding stoichiometric reagents that create waste—so catalysis is a named green-chemistry principle.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#催化 #绿色 #节能