Understanding Acids and Bases: Key Properties and Nomenclature
Dot-Point 1: investigate the correct IUPAC nomenclature and properties of common inorganic acids and bases (ACSCH067)
When it comes to chemistry, acids and bases are fundamental concepts that help us understand the behaviour of many substances, from household cleaners to industrial chemicals. Let’s take a closer look at these essential compounds, their properties, and how they are named.
What are Acids & Bases?
Acids are compounds that release hydrogen ions (H+) when dissolved in water. This makes them essential in various chemical reactions, such as those in our stomachs when digesting food.
On the other hand, bases are compounds that release hydroxide ions (OH-) in water. These compounds are crucial for neutralizing acids and are commonly found in products like soaps and cleaning agents.
Alkalis are simply water-soluble bases. In other words, all alkalis are bases, but not all bases are alkalis since some do not dissolve in water.
Common Acids and Bases to Know
Here are some of the most common acids and bases you'll come across in both everyday life and in the lab:
Acids:
Hydrochloric acid (HCl) – Found in stomach acid.
Nitric acid (HNO3) – Used in fertilizers and explosives.
Ethanoic (Acetic) acid (CH3COOH) – The main component of vinegar.
Sulfuric acid (H2SO4) – A strong acid used in car batteries and manufacturing.
Carbonic acid (H2CO3) – Found in carbonated beverages.
Phosphoric acid (H3PO4) – Common in soft drinks and fertilizers.
Citric acid (C6H8O7) – Found in citrus fruits.
Bases:
Sodium hydroxide (NaOH) – Also known as lye, used in soap making.
Ammonia (NH3) – A common cleaning agent.
Potassium hydroxide (KOH) – Used in the production of biodiesel.
Calcium hydroxide (Ca(OH)2) – Often used in water treatment and as a neutralizing agent.
Magnesium hydroxide (Mg(OH)2) – Commonly used as an antacid.
Sodium carbonate (Na2CO3) – Also known as soda ash, used in glass making.
Nomenclature: How Do We Name Acids?
The naming of acids depends on their chemical structure, and understanding how this works will help you identify acids and their properties more easily.
Acids with a Simple Anion (Hydrogen + Anion):
Take hydrochloric acid (HCl) as an example. It is hydrogen chloride when the compound is not in water, but when it dissolves in water, it becomes hydrochloric acid. This is because we drop the “-ide” ending and replace it with “-ic,” adding the prefix "hydro-" to indicate the presence of hydrogen.
Oxyacids (Acids with Oxygen):
For acids that contain oxygen, such as nitric acid (HNO3), sulfuric acid (H2SO4), and carbonic acid (H2CO3), the naming follows a simple pattern. If the compound ends in “-ate,” we change it to “-ic,” so HNO3 becomes “nitric acid,” H2SO4 becomes “sulfuric acid,” and H2CO3 becomes “carbonic acid.”
Acids with a Reduced Oxidation State:
Some acids are derived from oxyanions where the central atom has a lower oxidation state. For instance, nitric acid (HNO3) has nitrogen in the +5 oxidation state, while nitrous acid (HNO2) has nitrogen in the +3 state. In such cases, the suffix changes from “-ate” to “-ite” (e.g., HNO3 → “nitric acid” and HNO2 → “nitrous acid”).
