Difference Between

Sodium Chloride vs Potassium Chloride
 

Sodium chloride and potassium chloride are ionic compounds. Both are solids, where cations and anions are in a closed packed structure. Sodium and potassium are group 1 metals, which have the capability to make +1 cations. Chloride is the -1 anion made by group 7 element, chlorine. Since group 1 elements are electropositive and group seven elements are electronegative, their electronegativity difference is larger. So they form ionic bonds.

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. 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. Chlorine is a nonmetal and has the ability to form a -1 charged anion. Its electron configuration is written as 1s² 2s² 2p⁶ 3s² 3p⁵. Since the p sub level should have 6 electrons to obtain the Argon, noble gas electron configuration, chlorine has the ability to attract an electron. 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 sea water. 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.

Potassium Chloride

Potassium chloride, which is shown as KCl, is an ionic solid. It is in the form of a white color, odorless crystal. The crystal structure of this is a face-centered cubic structure. Molar mass of potassium chloride is 74.5513 g mol^-1. Its melting point is about 770 °C, and the boiling point is 1420 °C. Potassium chloride is mainly used to make fertilizer since plants need potassium for their growth and development. KCl, being a salt, is highly soluble in water. Therefore, it readily releases potassium into soil water, so that plants can take in potassium easily. This is also used in medicine and food processing. Further, as for the chemical purposes, potassium chloride is used in making potassium hydroxide and potassium metal.