Melting and dissolving in water to break ionic bonds and covalent bonds

1 Melting and ionic bonds, because it only shortens the distance between molecules and does not break ionic bonds.

2. Soluble in the bond between water and ions, because the ion crystal forms freely moving ions in the aqueous solution, breaking the ionic bond.

3. Covalent compounds are soluble in water, depending on what the compound is"Electrolytes"Still"Non-electrolyte".

If yes"Non-electrolyte"For example, the alcohol dissolution process does not ionize, the covalent bond is not broken, and the broken is van der Waals force.

b If yes"Electrolytes"For example, when Hcl H atom and Cl atom share a pair of electrons, when dissolved in water, H becomes H+, Cl becomes Cl-, and both become ions.

The original H-Cl covalent bond no longer exists.

4. Melting and covalent bonds, depending on whether they are atomic crystals or molecular crystals.

aIn the case of molecular crystals, such as HCl fusion is to shorten the distance between molecules without breaking the covalent bonds.

b If it is an atomic crystal, such as SiO2 melting is to break the covalent bond (this high school stage can only be memorized).

When melted, the ionic bonds are broken and the covalent bonds are continuous, whether it is a soluble or insoluble substance.

When soluble in water, both ionic and covalent bonds are broken (meaning soluble in water).

There is an example: magnesium chloride is used to decompose in the molten state when making metal mg, and aluminum oxide can be used in the production of AL, but aluminum chloride cannot be used, because aluminum chloride is a covalent compound and cannot ionize when melting.

Melt can be broken, and covalent bonds can only be broken when dissolved in water.

Because of the covalent compounds.

Dissolving in water does not necessarily break the covalent bonds.

If the compound is a strong electrolyte.

then all covalent bonds must be broken.

Because the strong electrolyte is completely ionized in water, all the covalent bonds are broken, forming free-moving ions.

If the compound is a weak electrolyte, it does not break all the covalent bonds.

Because the weak electrolyte is dissolved in water and is not completely ionized, part of the covalent bonds are broken and exist in the form of ions; Partial covalent bonds do not break and exist in molecular form.

If the compound is a non-electrolyte, it does not break the covalent bond.

Compounds formed mainly by covalent bonding are called covalent compounds. Compounds (such as CO2, ClO2, B2H6, BF3, NCL3, etc.) and most organic compounds formed by the atomic combination of different non-metallic elements are covalent compounds. In covalent compounds, there are generally separate molecules (formulas that fit the name).

Generally, covalent compounds have low melting and boiling points, are insoluble in water, and are in a molten state.

It is not conductive, and its hardness is smaller than that of Yunbu.

From the perspective of high school chemistry, water molecules are polar molecules, in which the electronegativity of hydrogen and oxygen atoms varies greatly, resulting in hydrogen atoms being electropositive and attractive to negatively charged anions, and oxygen atoms being positively charged and attractive to cations, and the two atoms form hydrogen bonds with cations and cations respectively, and this force is strong enough to break the covalent bonds.

From the perspective of quantum mechanics, chemical bonds are all superposition states of wave functions, and the positivity and negative properties of the hydrogen and oxygen atoms of water molecules are very strong, and the electrons and original traces of the electrons and original crackers that constitute the ionic posture closed bonds and covalent bonds cannot be regarded as perturbations, which will redistribute the original wave function and form a new wave function, which is reflected in the form of hydrogen bonds.

From the perspective of high school chemistry, water molecules are polar molecules, in which the electronegativity of hydrogen and oxygen atoms is quite different, resulting in hydrogen atoms being electropositive, which is attractive to negatively charged anions, and oxygen atoms are positively charged, and there is a virtual gravitational attraction on cations, and the two atoms form hydrogen bonds with cations and cations respectively, which is strong enough to break the covalent bonds.

From the perspective of quantum mechanics, chemical bonds are all superposition states of wave functions, and the hydrogen and oxygen atoms of the water file burner are very positively and negatively charged, and the electrons and atoms that constitute the ionic bond and the covalent bond cannot be regarded as perturbations, which will redistribute the original wave function to form a new wave function, that is, in the form of hydrogen bond.

A covalent bond refers to a strong chemical bond formed by two atoms sharing electrons. In chemical reactions, covalent bonds often need to be broken to form new molecular structures. However, some substances can be completely dissolved in water and significantly reduce the strength of the covalent bond and promote the reaction rate.

So what are these substances?

Normally, only polar substances are soluble in water because water molecules are polar molecules. If the atoms in a substance molecule have similar electronegativity and a relatively uniform charge distribution, then the molecule is non-polar and cannot interact with water. However, if there are some charged atoms or groups in the molecule, then it may be a polar molecule that can be dissolved through the interaction between the charges and the attraction of water molecules to each other.

Acid is a very common polar substance and a substance that is able to be completely soluble in water. When an acid molecule is dissolved in water, it releases negatively charged hydrogen ions (H+), which increases the number of hydrogen ions in the water molecule, thus changing the pH of the water. This acidic environment can break covalent bonds in certain molecules and facilitate the occurrence of chemical reactions.

Thus, we can say that acid is a substance that is capable of overcoming covalent bonds.

Apart from acids, there are other compounds that are able to dissolve in water and reduce the strength of the covalent bonds. For example, two basic substances, sodium hydroxide (NaOH) and potassium hydroxide (KOH), can also be completely dissolved in water and release positively charged hydrogen ions (OH-). These charged ions can break covalent bonds by attracting polar groups to other molecules.

Although it is not only acids that can overcome covalent bonds, acids are one of the most common spinal focal points. In fact, many acids can be used in chemical reactions as catalysts to accelerate the reaction rate. Acids have the property of promoting the rate of reactions because it can break the covalent bonds and leave behind the reactive site.

Therefore, when performing chemical reactions, we need to recognize the effect of acids on the strength of the covalent bonds of the cherry finch in order to make better use of them to accelerate the reaction rate.

In the molten state, the covalent bond will not be broken when the base is made, and it is the ionic bond that will be broken. Generally, metals and non-metals form ionic bonds, and non-metals form covalent bonds. At very high temperatures or when certain chemical reactions occur, the bonds are broken to form other substances.

A covalent bond is a type of chemical bond in which two or more atoms use their outer electrons to reach electron saturation under ideal conditions, thus forming a relatively stable and strong chemical structure called a covalent bond. Unlike ionic bonds, the atoms that enter the covalent bond do not show an outward charge because they do not gain or lose electrons.

Let's just say, not exactly. Take a look at the following explanations: First of all, be clear:

The intermolecular forces are not chemical bonds, and the intermolecular forces are much weaker than the forces between chemical bonds. Second, it is necessary to understand the concept between the three types of crystals: molecular crystals, ionic crystals, and atomic crystals.

In other words, add another source species, metal crystals. Remember common hail macro atom crystal examples: silicon carbide (Si), monocrystalline silicon (Si), diamond (C), silicon dioxide (SiO2), etc.

The melting and boiling point of atomic crystals is generally higher than 1000 degrees Celsius. Therefore, when comparing the melting and boiling points between molecular crystals, ionic crystals, and atomic crystals, atomic crystals are the highest. The melting and boiling point of metal crystals is uncertain, some are high and some are low.

Second, note the distinction between a set of concepts: melting and boiling point and stability. The melting and boiling point refers to the intermolecular forces, and the stability refers to the chemical bonds (the difference between chemical and intermolecular forces has already been mentioned) Note the effect of the presence of hydrogen bonds on the melting and boiling point of a substance:

Substances composed of N, O, F and H generally contain hydrogen bonds, which are not chemical bonds, but are a special intermolecular force, or it can be said that it is an intermolecular force. The melting and boiling point of substances containing hydrogen bonds is higher than that of other molecular crystals in the absence of limbs. (Note:.)

The general situation here refers to similar structures, such as Hi and HF, both of which are similar in structure, but HF contains hydrogen bonds, which helps HF have a higher melting and boiling point. In particular, this is a comparison between molecular crystals).Important note:

In special cases, there are also H and O in water vapor, but because the distance between the gas molecules is very large, the hydrogen bonds between them are approximately absent and can be directly considered to be none. However, in the liquid, solid H2O, there are still hydrogen bonds. The comparison of the melting and boiling point between molecular crystals is mainly based on their relative molecular mass, but this is only limited to molecular crystals with similar structures.

The melting and boiling points of two ionic crystals are not easy to compare, and under normal circumstances, there are no two ionic crystals in the title, at least I have not seen them so far. For your third point, not all substances have chemical bonds, such as noble gases, because they are all monoatomic molecules, so there are no chemical bonds. All typed by hand.

No copying! , 4, Questions about ionic bonds, chemical bonds, intermolecular forces, and melting and boiling point.

1.The melting and boiling point of sodium chloride and potassium chloride is related to the atomic radius of sodium and potassium, the atomic radius of potassium is larger than that of sodium, so the attraction to chlorine is weak, so the melting and boiling point of potassium chloride is less than that of sodium chloride. 2.

The relative molecular mass of hydrogen bromide is less than that of hydrogen iodide, so its melting and boiling point is 3To determine the melting and boiling point of similar substances, the radius of the ionic crystal is to be judged, and the relative molecular mass of the molecular crystal or the covalent bond is to be determined. This is because ionic crystals are going to break ionic bonds, while molecular crystals are intermolecular forces.

The third point is that I think about it myself, and I haven't learned it yet.