什么是Ionic化合物？

在化学中我们通常会遇到称为离子、阴离子、阳离子、离子化合物的术语，研究这些化合物是理解各种概念的必要条件。让我们了解为什么通常会形成离子，原子是由称为电子、质子和中子的粒子组成的。任何原子中电子和质子的数量相同，导致净电荷为零。当一个原子失去或获得电子时，因为电子带有负电荷而质子带有正电荷并保持不变，原子上的净电荷会发生变化，从而导致离子的形成。原子失去电子时形成正离子，而获得电子时形成负离子。如果一个原子的正离子与另一个原子的负离子结合形成离子化合物。

Ionic化合物

Ionic Compounds can be defined as the chemical compound formed by opposite charged ions held together by ions bonds or electrostatic forces.

Ionic键通常在金属和非金属之间形成。当原子失去电子形成阳离子时，原子总是倾向于获得稳定的电子构型，而当原子获得电子时形成阴离子，这两个带相反电荷的原子相互吸引形成离子键，该化合物称为Ionic化合物。

Ionic化合物通过静电力保持在一起，因为它们也称为Ionic化合物。当两个原子具有较大的电负性差异时，也会形成Ionic化合物，由于一个原子比另一个原子吸引电子更多，导致原子中电子的损失和电子的获得。

Ionic化合物的例子

• 氯化钠 (NaCl)

钠在其价壳中有一个电子以获得稳定的八位字节构型钠原子失去一个电子，因为质子数不变并且电子减少一个，净电荷变为+1，形成阳离子。而氯在其价壳中有 7 个电子，因此它需要一个电子才能稳定，它从钠中获得一个电子，导致钠和氯之间形成Ionic键，形成 NaCl。

• 氯化镁 ( MgCl ₂ )

镁在其价壳中具有两个电子以获得稳定的八位位组构型镁原子失去两个电子，因为质子的数量没有改变并且电子减少了两个，净电荷变为+2形成阳离子。而氯在其价壳中有 7 个电子，因此它需要一个电子才能变得稳定，它从镁中获得一个电子，因为镁失去了两个电子，而氯只能获得一个电子，两个氯原子与一个镁原子结合在一起，导致形成镁和氯之间的Ionic键形成 MgCl ₂ 。

Ionic化合物的性质

1. 晶体性质：Ionic化合物形成晶体结构，但其大小取决于阴离子和阳离子的大小。离子化合物的晶体结构是不带电荷的，因为许多阳离子与结合形成Ionic化合物的阴离子相等。
2. 硬而脆：Ionic化合物很硬，因为离子通过强大的静电力结合在一起。这些化合物很难破碎，因为它们被强大的力量固定，所以施加高压来破碎，因此离子化合物在自然界中很脆。
3. 高熔点和沸点：Ionic化合物坚硬，受强静电力吸附，不易断裂。为了打破这种强大的力量并克服它们之间的吸引力，需要高熔点和沸点。
4. 高融合和汽化焓：Ionic化合物通常比任何其他正常分子化合物具有更高的融合和汽化焓。它们的焓比分子化合物大 10-100 倍。
5. 溶解性：Ionic化合物可溶于水等极性溶剂。它们在非极性共价溶剂中的溶解度较低。
6. 水溶液或熔融形式的良导体：Ionic化合物在水溶液或熔融形式中充当良导体，因为离子化合物紧密堆积，不允许离子发生任何运动，因此使其成为不良导体但是，当它们处于含水或熔融形式时，离子可以自由移动，这使得它们在含水或熔融形式中成为良好的电导体。
7. 充当绝缘体：Ionic化合物在熔融或含水形式中充当良好的电导体，否则它们充当绝缘体。

Ionic化合物和共价化合物之间的区别

以下是Ionic化合物和共价化合物之间的区别：

Ionic Compounds	Covalent Compounds
Ionic Compounds are formed by the transfer of electrons between atoms	Covalent Compounds are formed by sharing of electrons between atoms
Ionic bonds are stronger than covalent bonds	Covalent bonds are weaker when compared to ionic bonds
The atoms that combine together to form Ionic Compounds are charged	The atoms that combine together to form Covalent Compounds are electrically neutral
Ionic Compounds are formed by atoms of different elements	Covalent Compounds are formed by atoms of the same or other elements
Ionic Compounds occur in solid-state at room temperature	Covalent Compounds mostly occur in solid, liquid and gaseous state
These compounds are soluble in water	These compounds are not soluble in water
Ionic compounds conduct electricity in molten or aqueous form	Covalent Compounds do not conduct electricity in any form
Ionic Compounds have high melting and boiling points	Covalent compounds have fewer melting and boiling points when compared to ionic compounds
Examples: NaCl, MgCl2, NaOH etc.	Examples: H2O, O2, Cl2 etc.

示例问题：

问题1：为什么Ionic化合物在固态不导电？

回答：

Ionic compounds conduct electricity due to the movement of electrons from one point to another point whereas in solid-state Ionic Compounds are strictly packed making the movement of ions impossible so, Ionic Compounds don’t conduct electricity in a solid state.

问题 2：Ionic化合物可溶于有机溶剂吗？

回答：

Ionic compounds are not soluble in organic solvents like petrol and kerosene they are only soluble in polar covalent solvents like water.

问题3：提到Ionic化合物最常见的特性？

回答：

Common properties that most Ionic Compounds share are:

• Ionic compounds are crystalline in nature
• They have high melting and boiling points
• They are good conductors of electricity in molten and aqueous form
• They are hard and brittle in nature

问题 4：解释Ionic化合物这个术语？

回答：

Ionic compounds are chemical compounds that are formed due to the transfer of electrons between oppositely charged ions that are held by electrostatic forces. These compounds are usually formed between metals and non-metals.

问题 5：提到一种日常用于家庭用途的Ionic化合物？

回答：

Ionic Compound that is most commonly used for domestic purposes is Sodium Chloride also known as Table Salt. If salt is observed in the magnifying glass a crystal structure can be seen also it is a bad conductor of electricity in the solid-state whereas it conducts electricity when dissolved in water.

问题 6：MgO 和 NaCl 哪个熔点和沸点最高？

回答：

Magnesium Oxide has higher melting and boiling points than sodium chloride. MgO has a melting point of around 2800 degrees celsius whereas NaCl has a melting point of around 801-degree celsius. This is because ionic bonding in Magnesium Oxide is stronger than Sodium Chloride due to the presence of more charges in Magnesium Oxide than in Sodium Chloride.

问题 7：Ionic化合物可以作为固态电解质吗？

回答：

No, Ionic Compounds cannot act as electrolytes in solid-state since they don’t conduct electricity they act as electrolytes in the aqueous or molten state because in order to act as conductor of electricity it involves movement of ions which is not possible in a solid-state.