Sais: Definição e Classificações - Brasil Escola

Summary

In this chemistry lesson, the focus is on salts, their definitions, classifications, and properties. The instructor explains how salts form through neutralization reactions between acids and bases, and then classifies them based on the presence of oxygen and the type of neutralization (total or partial). The lesson covers different types of salts, including neutral, acidic, basic, double, and hydrated salts. The properties of salts are discussed, such as high melting points, crystalline structure, solubility in water, and electrical conductivity. The session concludes with solubility rules for salts to aid understanding.

Takeaways

• 😀 Salts are compounds formed by the reaction of an acid and a base, resulting in a cation (other than H+) and an anion (other than OH-).
• 😀 Salts can be classified based on their oxygen content: oxygenated salts (with oxygen) and non-oxygenated salts (without oxygen).
• 😀 There are five main types of salts based on neutralization: neutral salts, acidic salts, basic salts, double salts, and hydrated salts.
• 😀 Neutralization is the process by which salts are formed, and it can be total or partial.
• 😀 Total neutralization occurs when an acid releases all its ionizable hydrogens and a base releases all its hydroxides, resulting in a neutral salt.
• 😀 Partial neutralization can be either of the acid (leading to acidic salts) or of the base (leading to basic salts).
• 😀 Acidic salts are formed from partial neutralization of an acid and contain ionizable hydrogen.
• 😀 Basic salts are formed when a base does not fully release all its hydroxyl groups, leaving some in the salt's composition.
• 😀 Double salts are formed when two acids react with one base or one acid reacts with two bases.
• 😀 Hydrated salts contain water within their crystal structure, referred to as water of hydration or crystallization.
• 😀 Salts typically have high melting and boiling points, defined crystalline structures, and are good conductors of electricity in their liquid or aqueous state.
• 😀 Salts are usually soluble in polar solvents, particularly water, where they undergo dissociation.

Q & A

What is a salt according to the script?

A salt is a compound formed by a cation (different from H+) and an anion (different from OH-) through a neutralization reaction between an acid and a base.

How can salts be classified according to the presence of oxygen?

Salts can be classified into two categories: oxygenated salts (salts containing oxygen) and non-oxygenated salts (salts that do not contain oxygen).

What is the difference between a neutralization total and a partial neutralization?

A total neutralization occurs when the acid releases all of its ionizable hydrogen ions and the base releases all of its hydroxide ions, forming a neutral salt. A partial neutralization happens when either the acid or the base does not release all of its ionizable components, resulting in an acidic or basic salt.

What is the characteristic of a neutral or normal salt?

A neutral salt is formed from a total neutralization, meaning it does not exhibit acidic or basic properties and consists of a cation different from H+ and an anion different from OH-.

What defines an acidic salt?

An acidic salt is formed when the acid does not release all of its ionizable hydrogen ions. The salt retains some of these hydrogen ions, giving it acidic properties.

How does a basic salt differ from an acidic salt?

A basic salt is formed when the base does not release all of its hydroxide ions. The presence of hydroxide ions in the salt gives it basic properties, unlike acidic salts which contain ionizable hydrogen.

What is a double or mixed salt?

A double or mixed salt is formed when two acids react with a base or when an acid reacts with two bases. It typically contains multiple cations or multiple anions in its formula.

What is a hydrated salt?

A hydrated salt is one that contains water molecules in its crystal lattice, known as water of hydration or crystallization.

What are the main properties of salts mentioned in the script?

Salts are solids at room temperature, have high melting and boiling points, possess well-defined crystalline structures, are good conductors of electricity when in liquid or aqueous form, and are generally soluble in polar solvents like water.

What happens when salts dissolve in water?

When salts dissolve in water, they undergo dissociation, breaking down into their respective ions, which is important for their electrical conductivity.