什么是基地? –定义,示例,类型,属性和用途
酸和碱是常见的化合物,当它们相互反应时,它们会相互作用产生盐和水。酸来源于拉丁词acere,意思是酸的。许多被科学家称为酸的化学物质在我们的日常生活中被使用。您早餐喝的橙汁或葡萄柚汁中含有柠檬酸(也称为维生素 C)。
当牛奶变酸时会产生乳酸。任何能够将质子(氢离子)转移到另一种化学物质的含氢材料都被归类为酸。碱是可以从酸中取出氢离子并接受它的分子或离子。酸性物质的特点是酸味。酸是一种分子,它可以提供 H+ 离子,同时在失去该离子后仍保持能量有利。已知蓝色石蕊在接触酸时会变红。
基地
- 基础化合物对它们有苦味。
- 大多数碱的质地是肥皂状的。
- 在石蕊试纸上进行测试时,在大多数情况下,它会将红色石蕊试纸转化为蓝色石蕊试纸。
- 在溶液中,碱性化合物也导电。
- 当碱性化合物溶解在水中时,会释放出 OH- 离子。
Examples:
NaOH, Ca(OH)2, Na2CO3, NH3, LiOH, KOH, CsOH, Ba(OH)2, RbOH, NaNH2, NaH, SiO2, Al2O3, MgO, CaO, LiCO3 on silica, KNH2 on alumina, BaO, BeO, KCN etc.
Many examples of bases may be found in everyday life. Many common household items or chemicals, such as drain cleaning, detergent, lubricating grease, baking soda or baking powder, soaps, toothpaste, mouthwash, chewing gum, hair dye, insecticides, and so on, are actually bases.
基地类型:
酸度、浓度和电离度是可用于对碱进行分类的三个变量。
- 基于酸度的碱基类型:
碱的酸度由存在的羟基离子的数量决定。根据酸度,碱分为三类:
- 单酸碱
- 二酸碱
- 三酸碱
- Monoacidic: Mono acidic bases are those that contain only one hydroxyl ion and interact with only one hydrogen ion. Mono acidic bases include NaOH, KOH, and others.
- Diacidic: Di acidic base is a base with two hydroxyl ions that interact with two hydrogen ions. Ca(OH)2, Mg(OH)2, and other di acidic bases are examples.
- Triacidic: Triacidic base is a type of base that comprises three hydroxyl ions and three hydrogen ions. Triacidic bases include Al(OH)3, Fe(OH)2, and others.
- 基于它们在水溶液中的浓度的碱基类型:
根据它们在水溶液中的浓度,碱分为两类:
- 浓缩碱
- 稀释碱
- Concentrated: The concentration of base in these types of bases is higher in the solution. Concentrated NaOH solution, for example.
- Diluted: These types of bases have a lower concentration of base in their aqueous solution. For instance, dilute NaOH, dilute KOH, and so on.
- 基于电离度的碱基类型:
溶液中碱的电离程度可用于对它们进行分类。它也被称为基础强度。溶于水时,会产生一定量的氢氧根离子。电离度区分两种类型的碱基。
- 强碱
- 弱碱基
- Strong: A strong base is one that dissociates entirely or to a large extent in water. For instance, NaOH, KOH, and so forth.
- Weak: A weak base is one that does not dissolve entirely or only dissociates to a very little level. For instance, NH4OH, and so on.
基地的性质:
- 基地的一般性质:
- 氢氧根离子 (OH–) 通过碱释放到水中。随着更多离子的释放,碱变得越强。
- 酸与碱反应。当酸和碱反应时,会形成水和一种称为盐的化合物。
- 由于石蕊的存在,碱基变成红蓝色。
蛋白质的结构可以通过碱基改变。基地具有这种品质,使它们感觉光滑。Soap是一种在潮湿时会在您的皮肤上变得异常光滑的基底。由于它们能够改变蛋白质的结构,一些强大的碱基是极其危险的。
由于人体皮肤含有许多蛋白质,因此溶于水的强碱(例如碱液)尤其有害。当这些强效碱与皮肤接触时,它们开始改变皮肤的结构。这可能导致灼伤。为避免对皮肤造成伤害,应谨慎使用强碱。
- 碱基的物理性质:
- 碱味苦涩——碱性食品原料很少。谨慎品尝基料更为重要。由于更强的碱能够使蛋白质变质,因此品尝碱比品尝酸更有害。
- 碱在水溶液中释放氢氧根离子。
- 碱在中和反应中中和酸-术语“反应”是指当酸和碱结合时产生水和盐。其中“Y”象征性地是酸“HY”的阴离子。反应是:“X”是碱基“XOH”的阳离子,“XY”是结果中的盐。 [ HY + XOH → HOH + XY ]
- 碱基使蛋白质变性——这就解释了为什么当你靠近碱基时你的手会感觉很滑。易溶于水的强碱,如钠或钾碱液,是极其有害的,因为蛋白质构成了人体结构材料的很大一部分。明智地使用强碱可以防止严重的肉损伤。
- 碱将红色石蕊变成蓝色——这并不是说石蕊是唯一可用的酸碱指示剂;只是它是最古老的。
- 碱的化学性质:
- 碱与金属的反应:当碱(碱)与金属反应时,会产生盐和氢气。
碱 + 金属 → 盐 + 氢
Examples:
- When sodium hydroxide interacts with aluminium metal, sodium aluminate and hydrogen gas are generated.
2 NaOH + 2 Al + 2 H2O → 2 NaAlO2 + 2 H2
- When sodium hydroxide interacts with zinc metal, it produces hydrogen gas and sodium zincate.
2 NaOH + Zn → Na2ZnO2 + H2
- 非金属氧化物与碱的反应:当非金属氧化物与碱反应时会形成盐和水。
非金属氧化物 + 碱 → 盐 + 水
Example:
- Ca(OH)2 + CO2 → CaCO3 + H2O
- 碱/碱与铵盐的作用:当碱与铵盐反应时会产生氨。
碱 + 铵盐 → 盐 + 水 + 氨
Example:
- When calcium hydroxide reacts with ammonium chloride, calcium chloride water and ammonia are produced.
Ca(OH)2 + NH4Cl → CaCl2 + H2O + NH3
基地的用途:
- 氢氧化钠用于制造soap和纸张。氢氧化钠 (NaOH) 也用于生产人造丝。
- 漂白粉由通常称为熟石灰或氢氧化钙的 Ca(OH)2 制成。
- 氢氧化钙用于制造用于绘画和装饰的干燥混合物。
- 氢氧化镁,俗称氧化镁乳,是一种广泛使用的泻药。它也被用作抗酸剂,因为它可以减少人胃中过多的酸度。
- 在实验室中,氢氧化铵是一种关键试剂。
- 熟石灰可用于中和土壤中任何过量的酸度。
示例问题:
问题1 什么是碱基?
回答
- Base compounds have a bitter flavour to them.
- The texture of most bases is soapy.
- When tested on litmus paper, it transforms red litmus paper into blue litmus paper in most cases.
- In solution, the base compounds also conduct electricity.
- When base compounds are dissolved in water, OH- ions are liberated.
问题2 碱基的作用是什么?
回答
At home, we employ bases as cleaning agents and antacids. Soaps, lye (which is used in oven cleansers), magnesia milk, and Tums are all examples of popular homemade bases. Each of them has a pH greater than seven, can consume free hydrogen, and neutralise acids.
Question-3 如何确定基地的位置?
回答
Count the hydrogens on each component before and after the reaction to determine if it is an acid or a basic. This product is acid when the amount of hydrogens decreases (donates ions of hydrogen). This material serves as the foundation when the amount of hydrogen in the atmosphere rises (accepts ions of hydrogen).
问题 4 酸和碱之间最重要的区别是什么?
回答
Acids and bases are two types of corrosive chemicals. Acidic materials have a pH value between 0 and 7, while bases have a pH value between 7 and 14. Acids are ionic chemicals that break down in water to create the hydrogen ion (H+).
Question-5 碱的物理性质是什么?
回答
- They have a bitter taste to them.
- Their aqueous solutions have a soapy quality to them.
- They change the colour of litmus paper from red to blue.
- Their aqueous solutions are electrically conductive.
- With the release of hydrogen gas, bases react with metals to generate salt.
问题6 氢氧化钙与氯化铵反应会发生什么?
回答
When calcium hydroxide reacts with ammonium chloride, calcium chloride water and ammonia are produced.
Ca(OH)2 + NH4Cl → CaCl2 + H2O + NH3
问题 7 当氢氧化钠与金属锌相互作用时会发生什么?
回答
When sodium hydroxide interacts with zinc metal, it produces hydrogen gas and sodium zincate.
2 NaOH + Zn → Na2ZnO2 + H2