Acids and bases are everywhere. Seriously. They are in all households, hidden in bathroom cabinets and refrigerators. The problem is that not many people take the time to explore and learn about them. They have probably tasted acids before (and bases too, if they have eaten soap) and used bases for cleaning. Here are the answers to some common questions about acids and bases.
What are acids and bases?
Based on the Arrhenius Theory, an acid is a substance that can dissociate or break apart in water and creates hydrogen ions (H+) during the process. A hydrogen ion is a hydrogen atom that has lost one electron. There are actually two types of acids: oxyacids and binary acids. What’s the difference? Oxyacids are composed of hydrogen and another element. Binary acids are composed of hydrogen and a polyatomic ion that contains at least one oxygen atom. A base is a substance that can dissociate in water as well, but produces hydroxide ions (OH-) instead.
What are their properties?
Acids have, but are not limited to only having, the following properties:
- Have a pH less than 7
- Taste sour
- Create a burning sensation when touched
- React with active metals (usually Alkali Metals and Alkaline-Earth Metals) to produce hydrogen gas
- React with carbonates (types of polyatomic ions) to produce carbon dioxide
- Have a pH less than 7
- Taste bitter
- Feel slippery when touched
- React with phenolphthalein (an acid-base indicator) to produce a pink-coloured solution
What are neutralization reactions?
Neutralization reactions are also called acid-base reactions. They are a specific type of double displacement reaction. In a neutralization reaction, an acid and a base are both reactants and the products will always be water (H2O) and a salt. Do not mistaken this “salt” with the table salt used in food. In chemistry, a salt is a ionic compound that can be dissolved into an aqueous solution.
What makes acids and bases strong?
The strength of an acid or base depends on how much of the acid or base breaks down in water. If the acid or base completely or almost completely dissociates in water, then the substance is strong. If the acid or base barely breaks down in water, then the substance would be weak.
Strong Acids
For binary acids, only hydrofluoric acid (HF) is weak. All other binary acids dissociate completely or almost completely. For oxyacids, the acid will be strong if the number of oxygen atoms is greater than the number of hydrogen ions that can be dissociated by at least 2. For example, chloric acid (HClO3) is a strong acid but chlorous acid (HClO2) is a weak acid.
Strong Bases
The hydroxides of the Alkali and Alkaline-Earth Metals are considered strong bases, with the exception of beryllium hydroxide.
What makes acids and bases strong?
The strength of an acid or base depends on how much of the acid or base breaks down in water. If the acid or base completely or almost completely dissociates in water, then the substance is strong. If the acid or base barely breaks down in water, then the substance would be weak.
Strong Acids
For binary acids, only hydrofluoric acid (HF) is weak. All other binary acids dissociate completely or almost completely. For oxyacids, the acid will be strong if the number of oxygen atoms is greater than the number of hydrogen ions that can be dissociated by at least 2. For example, chloric acid (HClO3) is a strong acid but chlorous acid (HClO2) is a weak acid.
Strong Bases
The hydroxides of the Alkali and Alkaline-Earth Metals are considered strong bases, with the exception of beryllium hydroxide.
