Chemical Formula for Salt

Salts form one of the oldest dietary ingredients for mankind. They have existed since thousands of millennium and besides a popular food preservative, they have also been used in adding flavor to dishes and food. In chemistry, salts are classified as chemicals that have various characteristic features and properties. Salts are chemical compounds that are generally formed after the reaction of bases and acids.

Generally, when asked about the chemical formula for salt, students come up with the answer NaCl. Undoubtedly, NaCl is the chemical formula for table salt. However, in general, the molecular formula for salt depends on various chemical elements or compounds that are reacting in the chemical reaction. NaCl or sodium chloride, the salt that we use in our daily diets is the simplest and most popular salt that is known to us. However, in chemistry, salts are separately categorized as a group of chemicals with their own features and properties.

Cations and Anions List
To know a chemical formula, it's necessary that one should be aware of various cations and anions that are necessary in the formation of the compounds. The table given below gives various cations/anions and their symbols along with the charge on them. These will be helpful in arriving on a particular salt formula.

Cations		Anions
Ion Name	Symbol	Ion Name	Symbol
Aluminum	Al3+	Acetate	CH3COO-
Ammonium	NH+	Borate	BO33-
Arsenic(III)	Ar3+	Bromate	BrO3-
Arsenic(V)	Ar5+	Bromide	Br-
Barium	Ba2+	Carbonate	CO32-
Beryllium	Be2+	Chloride	Cl-
Bismuth(III)	Bi3+	Chlorate	ClO3-
Bismuth(V)	Bi5+	Chlorite	ClO2-
Cadmium	Cd2+	Hypochlorite	ClO-
Chromium(III)	Cr3+	Chlormate	CrO42-
Cobalt(II)	Co2+	Cyanide	CN-
Copper(I)	Cu+	Iodate	IO3-
Hydrogen	H+	Dichromate	Cr2O72-
Iron (II)	Fe2+	Dihydrogen Phosphate	H2PO4-
Tin(II)	Sn2+	Ferricyanide	Fe(CN)64-
Iron (III)	Fe3+	Fluoride	F-
Lead(II)	Pb2+	Iodide	I-
Lead(IV)	Pb4+	Oxide	O2-
Silver	Ag2+	Nitrate	NO3-
Zinc	Zn2+	Nitrite	NO2-
Mercury(I)	Hg22+	Permanganate	MnO4-
Mercury(II)	Hg2+	Hydroxide	OH-
Gold(I)	Au+	Peroxide	O22-
Gold(III)	Au3+	Perchlorate	ClO4-
Tin(IV)	Sn4+	Ferrocyanide	Fe(CN)63-
Sodium	Na+	Amide	NH2-
Lithium	Li+	Hydrogen Carbonate	HCO3-
Potassium	K+	Sulfate	SO42-
Rubidium	Rb+	Sulfite	SO3-
Cesium	Cs+	Hydrogen Sulfate	HSO4-

Steps to Derive the Chemical Formula
As mentioned earlier, using these symbols, we can know the chemical formula for various salts. Various steps to derive its formula have been discussed further.

• Determine the cations and anions in the salt formula. Every salt is made of cations and anions. Memorize the cations and anions list properly.
• The formula for chemical salt is always written with cations first and then the anions. That means, you write sodium chloride and not chloride sodium.
• A salt is always neutral which means total charge on anions and cations must be equal. To do this while formulating, we have to use cross multiply rule.

To understand the procedure better, we must study some examples.

Example #1: Determine the Formula for Sodium Sulfate
This salt consists of sodium (cation) and sulfate ions (anion).

Sodium Ion → Na⁺
Sulfate Ion → SO₄^2-

Just for convenience in understanding, we will use square brackets to separate cations, anions and the element. Therefore,

[Na]⁺ [SO₄]^2-

[Na]_2- [SO₄]₊ (Remember cross multiply rule. So cross multiply charges on respective ions)

Na₂SO₄ (Remove square brackets and charges)

Example #2: Determine the formula for Barium Oxide
This salt consists of barium (cation) and oxide (anions) ions.

Barium → Ba²⁺
Oxide → O^2-

[Ba]²⁺ [O]^2-

[Ba]_2- [O]₂₊

BaO

Likewise, once you are aware of cations and anions, it's very easy to come up with the chemical formula for any salt. The chemical formula for table salt is sodium chloride and it is also derived from the sodium and chloride cations and anions respectively. The chemical formula of kosher salt is NaCl, which is a type of salt popularly used for seasoning in hotels and kitchens. Salts undoubtedly are one of the most important compounds in the world of chemistry.