IB Chemistry HL - CHAPTER 8

Brønsted-Lowry acid

A Brønsted-Lowry acid is a species that gives away a proton.

Brønsted-Lowry base

A Brønsted-Lowry base is a species that accepts a proton (H^+) using its lone pair of electrons.

Conjugate acid-base pair

A conjugate acid-base pair is two species that are different from each other by a H{^+}-ion.

Amphiprotic

Amphiprotic describes a substance that can both accept or donate a proton.

Amphoteric

Amphoteric describes a substance that have the ability to act as both an acid and base.

Acid + metal

→ salt + hydrogen

Acid + metal hydroxide

Acid + metal oxide

→ salt + water

Acid + metal carbonate

→ salt + water + carbon dioxide

Acid + metal hydrogencarbonate

→ salt + water + carbon dioxide

How to make different types of salt

This is how:

Neutralization reaction

A neutralization reaction is: Acid + base (alkali) → salt + water

Indicators

Indicators are weak acids and bases where the conjugate bases and acids have a different color.

* A good indicator gives a very sharp colour change at the equivalence point.

pH equation

pH = -log\[H^+\]

Water at 298

See picture.

K_w

See picture.

Strong acid

A strong acid is an acid that dissociates almost completely in aqueous solutions.

Weak acid

A weak acid is an acid that partially dissociates in aqueous solutions.

Strong base

A strong base is a base that dissociates almost completely in aqueous solutions.

Weak base

A weak base is a base that parially dissociates in aqueous solutions.

What does strong acids produce?

In general strong acids produce weak conjugate bases and weak acids produce strong conjugate bases.

What does strong bases produce?

In general strong bases produce weak conjugate acids and weak bases produce strong conjugate bases.

How can strong and weak acids be distinguished

* pH value
* Electrical conductivity
* Reactivity

Acid rain

Acid rain is defined is rain with a pH lower than 5.6.

Acid deposition

Acid deposition includes all processes by which acidic components leave the atmosphere

Wet acid deposition

Wet acid deposition refers to rain, snow, sleet, hail, fog, mist and dew.

Dry acid deposition

Dry acid deposition refers to acidic particles and gases that fall to the ground as dust and smoke.

Acidrain droplets of sulfurous acid

See picture.

Acidrain droplets of sulfuric acid

See picture.

Acidrain droplets of nitrous and nitric acids

See picture.

Acidrain droplets of nitic acid

See picture.

Effects of acid deposition on materials

See picture.

Effects of acid deposition on plants

* Acid particles can block stomata and prevent gaseous exchange
* Acid rain can fall on soils and wach away important minerals leaving them unavailable to plants
* Aluminium ions are released from rocks are toxic to many plants

Effects of acid deposition on water

See picture.

Effects of acid deposition on human health

See picture.

Pre-combustion removal of sulfur

Pre-combustion removal of sulfur is a method of removing sulfur and takes place for coal and petroleum, although it is expensive to remove all the sulfur, so a small percentage often remains.

Hydrodesulfurization

Hydrodesulfurization is the process of removing sulfur by reacting it with hydrogen.

Post-combustion removal of sulfur

Post-combustion removal of sulfur is a method of removing sulfur from coal and is carried out on in coal-fired power stations.

How is post-combustion removal of sulfur done?

Post-combustion removal of sulfur is conducted by passing waste gases through a wet slurry of calcium oxide and calcium carbonate