Larutan Asam Basa (1) | Teori Asam dan Basa | Kimia Kelas 11

Summary

In this video, the presenter explains the theories of acids and bases for 11th-grade chemistry, covering Arrhenius, Bronsted-Lowry, and Lewis theories. The Arrhenius theory defines acids as substances releasing H+ ions in water and bases as those releasing OH- ions. The Bronsted-Lowry theory describes acids as proton donors and bases as proton acceptors. The Lewis theory defines acids as electron pair acceptors and bases as electron pair donors. The video includes examples and explains concepts like acid-base conjugates and amphiprotic species, providing a clear understanding of these fundamental theories.

Takeaways

• 📚 There are three theories that explain acids and bases: Arrhenius, Bronsted-Lowry, and Lewis.
• ⚗️ According to Arrhenius, an acid is a substance that releases H+ ions when dissolved in water, like HCl and H2SO4.
• 🧪 Arrhenius defines a base as a substance that releases OH- ions in water, such as NaOH and Ca(OH)2.
• 🔬 Valency of acids and bases indicates the number of H+ or OH- ions produced from one mole of the substance.
• 🧫 A monoprotic acid releases one H+ ion, a diprotic acid releases two, and a triprotic acid releases three H+ ions.
• 🔍 Bronsted-Lowry theory defines an acid as a proton donor and a base as a proton acceptor.
• 🧩 In Bronsted-Lowry theory, acids form conjugate bases by losing a proton, and bases form conjugate acids by gaining a proton.
• 🌀 Amphiprotic species can act as both acids and bases, like NH3 and H2O.
• 🔄 According to Lewis theory, an acid is a molecule or ion that accepts an electron pair, and a base donates an electron pair.
• 🔧 Lewis theory focuses on the transfer of electron pairs rather than protons, unlike Bronsted-Lowry theory.

Q & A

What is the Arrhenius definition of an acid?

According to Arrhenius, an acid is a substance that can release H+ ions when dissolved in water. For example, HCl dissociates in water to produce H+ and Cl- ions.

What is the Arrhenius definition of a base?

According to Arrhenius, a base is a substance that releases OH- ions when dissolved in water. For example, NaOH dissociates in water to produce Na+ and OH- ions.

What are the valencies of acids and bases according to Arrhenius?

The valency of an acid indicates the number of H+ ions released per molecule of the acid, while the valency of a base indicates the number of OH- ions released per molecule of the base. For example, HCl has a valency of 1, while H2SO4 has a valency of 2.

What is a monoprotic acid? Can you give an example?

A monoprotic acid is an acid that releases one H+ ion per molecule. An example is HCl.

What is the Bronsted-Lowry definition of an acid and a base?

According to Bronsted-Lowry, an acid is a proton (H+) donor, and a base is a proton (H+) acceptor.

What are conjugate acid-base pairs in the Bronsted-Lowry theory?

Conjugate acid-base pairs are two species that differ by one H+ ion. For example, HCl and Cl- form a conjugate acid-base pair, as do H2O and H3O+.

Can you explain what an amphiprotic species is?

An amphiprotic species can act as either an acid or a base. It can donate or accept a proton. Examples include NH3 and H2O.

What is the Lewis definition of an acid and a base?

According to Lewis, an acid is a molecule or ion that can accept an electron pair, while a base is a molecule or ion that can donate an electron pair.

How can you distinguish between a Lewis acid and a Lewis base using their structure?

A Lewis base will have a lone pair of electrons that it can donate, while a Lewis acid will have an empty orbital to accept an electron pair. For example, NH3 is a Lewis base because it has a lone pair of electrons, while BF3 is a Lewis acid because it has an empty orbital.

What is an example of a Lewis acid-base reaction?

An example of a Lewis acid-base reaction is the interaction between NH3 and BF3. NH3 donates its lone pair of electrons to BF3, forming a coordinate bond.