states Chemistry

17 个科学问题 · 化学 Chemistry

本页目录

为什么有时热水比冷水结冰更快?

Why can hot water sometimes freeze faster than cold?

姆潘巴效应指特定条件下热水可能先结冰,可能与蒸发失水、对流、溶解气体差异有关,机制仍有争议,依赖具体条件。
The Mpemba effect: under some conditions hot water freezes faster, possibly via evaporation, convection, or dissolved-gas differences; the mechanism is debated and condition-dependent.
难度 专业 · 适合 高中(15-18) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据结论有争议 · Contested
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#姆潘巴 #反常 #结冰

为什么氦在常压下再冷也不结成固体?

Why won't helium solidify no matter how cold at 1 atm?

量子零点能很大,让氦原子在1大气压下无法排成晶格,故不固化,必须加压才可能成固;液氦还能呈现超流动性。
Large quantum zero-point energy keeps helium atoms from locking into a lattice at 1 atm, so it won't solidify without pressure; liquid helium also shows superfluidity.
难度 专业 · 适合 高中(15-18) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#氦 #零点能 #超流

杠杆规则怎么读二元相图?

How does the lever rule read a binary phase diagram?

在两相区的某温度下,两相的比例由连接线按“杠杆”反比分割,靠近哪一端则哪一相更多。
At a temperature in the two-phase region, phase fractions split inversely along the tie-line like a lever; the nearer end gives the larger phase amount.
难度 专业 · 适合 大众 CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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Atkins, de Paula, Keeler,《Atkins' Physical Chemistry》第11版,Oxford University Press,2018

P. Atkins, J. de Paula and J. Keeler, Atkins' Physical Chemistry, 11th ed., Oxford University Press, 2018

#杠杆规则 #相图 #两相区

为什么微波加热纯水可能突然炸开?

Why might microwaved pure water suddenly burst?

水可过热到沸点以上却无气泡(无凝结核),受到扰动时剧烈暴沸喷出,放一根木勺提供气泡核可防。
Water can superheat above boiling with no bubbles (no nuclei); disturbance causes violent bumping. A wooden spoon provides nucleation sites.
难度 进阶 · 适合 大众 CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#过热 #暴沸 #微波

水的相图有什么特别之处?

What is special about water's phase diagram?

固-液线向左倾斜,因为冰比水轻(密度反常),加压反而使冰熔化;三相点在约 0.01°C、611 Pa。
The solid-liquid line slopes left because ice is less dense than water (density anomaly), so pressure melts ice; the triple point is ~0.01°C, 611 Pa.
难度 进阶 · 适合 大众 CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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Atkins, de Paula, Keeler,《Atkins' Physical Chemistry》第11版,Oxford University Press,2018

P. Atkins, J. de Paula and J. Keeler, Atkins' Physical Chemistry, 11th ed., Oxford University Press, 2018

#相图 #水 #密度反常

为什么很纯的水在冰箱可低于0°C仍不结冰?

Why can very pure water stay liquid below 0 C in a freezer?

缺少凝结核时,液态水能过冷到冰点以下仍保持液态;一旦投入冰晶或震动,瞬间大量结晶。
Without nucleation sites, pure water can supercool below 0 C and stay liquid; a seed crystal or shake triggers sudden freezing.
难度 进阶 · 适合 大众 CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#过冷 #凝结核 #结冰

为什么升华需要吸热?

Why does sublimation need heat?

固体直接变气体要克服粒子间作用力,因而吸收能量。
Going straight from solid to gas overcomes intermolecular forces, absorbing energy.
难度 进阶 · 适合 初中(12-15) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#升华 #吸热 #相变

为什么液体有表面张力?

Why does liquid have surface tension?

表面分子受内部分子吸引更强,使表面像一层弹性膜。
Surface molecules are pulled inward more strongly, making a skin-like surface.
难度 进阶 · 适合 初中(12-15) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#表面张力 #内聚 #液体

为什么加压能让气体液化?

Why does pressure liquefy a gas?

加压缩小分子间距,让分子间引力把它们拉成液体。
Pressure shrinks distances so intermolecular attraction pulls molecules into liquid.
难度 进阶 · 适合 初中(12-15) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#加压 #液化 #气体

为什么气体会充满整个容器?

Why does gas fill its container?

气体分子运动很快且间距大,会向各处扩散。
Gas molecules move fast and far apart, spreading everywhere.
难度 入门 · 适合 小学低段(6-8) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#气体 #扩散 #分子

为什么冰块在屋里会化成水?

Why does an ice cube melt into water indoors?

屋里比冰箱暖,冰受热就变成了水。
Indoors is warmer than the freezer, so the ice gets heat and turns to water.
难度 入门 · 适合 幼儿(3-6) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source

Atkins, de Paula, Keeler,《Atkins' Physical Chemistry》第11版,Oxford University Press,2018

P. Atkins, J. de Paula and J. Keeler, Atkins' Physical Chemistry, 11th ed., Oxford University Press, 2018

#冰 #融化 #热

液晶屏靠什么显示图像?

How does a liquid-crystal display form images?

液晶在电场下改变分子取向,转动偏振光以控制明暗,再配合彩色滤光片成像。
Liquid crystals change orientation under electric field, rotating polarized light to control brightness, combined with color filters for images.
难度 入门 · 适合 大众 CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source

Atkins, de Paula, Keeler,《Atkins' Physical Chemistry》第11版,Oxford University Press,2018

P. Atkins, J. de Paula and J. Keeler, Atkins' Physical Chemistry, 11th ed., Oxford University Press, 2018

#液晶 #显示 #偏振

为什么干冰不化成水而是冒白烟消失?

Why does dry ice vanish with white smoke instead of melting to water?

干冰是固体二氧化碳,常压下直接升华成CO2气体,周围冷气使空气中水汽凝结成白雾,看起来像冒烟,其实那白雾是水不是CO2。
Dry ice is solid CO2; at room pressure it sublimes to gas, and the cold makes ambient water vapor condense into white fog—the smoke is water, not CO2.
难度 入门 · 适合 幼儿(3-6) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#干冰 #升华 #二氧化碳

为什么樟脑丸放着会变小却不留水渍?

Why do mothballs shrink without leaving liquid?

樟脑(或萘)在室温下会升华,直接从固体变成气体防蛀,所以变小却不见液体;但萘有一定毒性,现多用替代物。
Camphor (or naphthalene) sublimes at room temperature—solid to gas—so it shrinks without liquid; naphthalene is somewhat toxic, now often replaced.
难度 入门 · 适合 小学低段(6-8) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#樟脑 #升华 #防蛀

水在0度结冰、100度沸腾,这个数字是永远不变的吗?

Does water always freeze at zero and boil at one hundred — are those numbers fixed forever?

只在标准大气压下成立。在青藏高原,气压低,水八九十度就沸腾了,所以高原煮饭要用高压锅强行加压;高压锅里气压可达两个大气压,水温能到120度,炖肉更快。冰点也随压力微变。化学课本上的常数都附带标准状况这个小字条款——条件变了,数字跟着变。
Only at standard atmospheric pressure. On the Tibetan Plateau low pressure boils water at eighty or ninety degrees, hence pressure cookers forcing higher pressure so water reaches 120 degrees for faster stews. Freezing shifts slightly with pressure too. Textbook constants carry fine print called standard conditions — change conditions, numbers move.
难度 入门 · 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
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《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

#沸点 #气压 #高压锅原理

为什么湿衣服晾一晾就干了?

Why do wet clothes dry when hung up?

衣服里的水慢慢变成水汽飞到空气里,衣服就干啦。
The water in clothes slowly turns into vapor and floats into the air, so they dry.
难度 入门 · 适合 幼儿(3-6) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source

Atkins, de Paula, Keeler,《Atkins' Physical Chemistry》第11版,Oxford University Press,2018

P. Atkins, J. de Paula and J. Keeler, Atkins' Physical Chemistry, 11th ed., Oxford University Press, 2018

#衣服 #晾干 #水

为什么固体有固定形状?

Why do solids keep their shape?

固体粒子在固定晶格上有序排列,只能在原地振动。
Solid particles sit in fixed lattices and only vibrate in place.
难度 入门 · 适合 小学低段(6-8) CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
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傅献彩 等,《物理化学》第5版,高等教育出版社,2005

Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005

#固体 #晶格 #形状