The name of every salt consists of two parts. The first part comes from the metal, and the second part comes from the acid. To name a salt, it’s important to follow this simple structure:
For example, when copper carbonate reacts with sulfuric acid, it produces the salt copper sulfate along with carbon dioxide and water. The equation for the reaction is:
Copper carbonate + Sulfuric acid → Copper sulfate + Carbon dioxide + Water
Salts have no overall charge because the sum of the charges on the ions that make up the salt is equal to zero. The table below shows some common ions and their charges.
|Group 1 metals||M⁺ (e.g. Na⁺, K⁺)|
|Group 2 metals||M²⁺ (e.g. Mg²⁺, Ca²⁺)|
|Group 7 halides||X⁻ (e.g. Cl⁻, Br⁻)|
If we know the ions present in a salt, we can work out the formula by balancing the charges.
For example, let’s look at the salt formed by the neutralisation reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl). The products of this reaction are water and sodium chloride (NaCl).
NaOH + HCl → NaCl + H2O
The sodium ion (Na⁺) has a charge of +1, while the chloride ion (Cl⁻) has a charge of -1. To balance the charges, we need one sodium ion and one chloride ion, which gives us the formula NaCl.
What is the formula of sodium carbonate?