Difference Between Sodium Chloride and Sodium Iodide

Sodium Chloride vs Sodium Iodide

Sodium, which symbolized as Na is a group 1 element with the atomic number 11. Sodium has properties of a group 1 metal. Its electron configuration is 1s2 2s2 2p6 3s1. It can release one electron, which is in 3s sub orbital and produce a +1 cation. Electronegativity of sodium is very low, allowing it to form cations by donating an electron to a higher electronegative atom (like halogens). Therefore, sodium often makes ionic compounds like sodium chloride and sodium iodide.

Sodium Chloride

Sodium chloride, which is also known as salt, is a white color crystal with the molecular formula NaCl. Sodium chloride is an ionic compound. Sodium is a group 1 metal, thus forms a +1 charged cation. Chlorine is a nonmetal and has the ability to form a -1 charged anion. With the electrostatic attraction between the Na+ cation and the Cl- anion, NaCl has obtained a lattice structure. In the crystal, each sodium ion is surrounded by six chloride ions, and each chloride ion is surrounded by six sodium ions. Due to all the attractions between ions, the crystal structure is more stable. The number of ions present in the sodium chloride crystal varies with the size of it. Sodium chloride is easily soluble in water and makes a salty solution. Aqueous sodium chloride and molten sodium chloride can conduct electricity due to the presence of ions. NaCl is normally produced by evaporating seawater. It can also be produced by chemical methods, such as adding HCl into sodium metal. These are used as food preservatives, in food preparations, as a cleansing agent, for medical purposes, etc. In order to make iodized salt, people add inorganic iodine sources like potassium iodate, potassium iodide, sodium iodate or sodium iodide, to refined sodium chloride.

Sodium Iodide

The chemical formula of sodium iodide is NaI. This is a white color crystalline, odorless solid, which readily dissolves in water. Iodine is a halogen, which can form -1 charged ions. Together with Na+ cations, iodide ions make large lattice structures. Molar mass of the NaI ionic compound is 149.89 g/mol. Its melting point is 661 °C, and the boiling point is 1304 °C. Sodium iodide is mainly used as an additive to salt, to prevent iodine deficiency. Iodine is a trace element, which is needed in our body. Thyroid gland act as the iodine storage and for its efficient functioning in making hormones like thyroxin, triiodothyronine and calcitonin, iodine is required. Goiter or swollen thyroid glands are a symptom of iodine deficiency. 150 μg of iodine is required daily for a healthy body. Sodium iodide is added to salt and is given to people with the iodine deficiencies to overcome these problems. When NaI has radioactive iodides like I-123, these compounds can be used for radio imaging or treat cancers.


What is the difference between Sodium Chloride and Sodium Iodide?

• Sodium chloride is shown as NaCl. The chemical formula of sodium iodide is NaI.

• In NaCl, sodium is bonded with the halogen chlorine, which is more electronegative than Iodine in NaI.

• Sodium chloride is more abundant than sodium iodide.

• NaI is more soluble in water than NaCl.

• Sodium chloride is commonly known as salt and sodium iodide is an additive to salt to reduce the iodine deficiency in human.