Difference between Salt and Sodium

Published on December 1, 2016

When people talk about going through a low-sodium diet, they are probably referring to a diet that has less salt. To the layperson, salt and sodium are one and the same. However, the two substances have very different properties, such as appearance and chemical reactivity. This article will discuss the differences between salt and sodium.

Definitions

Salt vs Sodium
Pink Himalayan salt in block and flake form

Salt is a common term for sodium chloride, a chemical that is approximately 40% sodium and 60% chlorine. It has a long history as a flavoring and as a preservative. Because salt was used as currency in the Roman Empire, the word “salary” is derived from the Latin word for salt and it means a working wage. 

Most salt is white in color and comes in either solid blocks or crystals. The most common sources of salt include seaside salt pans, salt mines, or evaporating pools near mineral-rich springs. 

Pure sodium chloride exists very rarely in nature, and most salt used for food or commercial purposes contains trace amounts of other elements, such as iodine. It dissolves very easily in water. Solid salt by itself does not conduct electricity; however, water that contains salt is a very good electric conductor. Thus, salt solutions are classified as “electrolytes.”

Salt melts at 801 degrees Celsius (1,473.8 degrees Fahrenheit) and boils at 1,465 degrees Celsius (2,669 degrees Fahrenheit). A salt solution also alters the physical properties of water, such as the freezing and boiling points.

Sodium
Sodium metal in block form

Sodium is an element that is present all over nature. However, the element itself does not exist on its own naturally. To obtain pure sodium, chemists have to extract it from its compounds, such as salt. The first successful attempt at this process took place in 1807.

Pure sodium is a silvery-white metal that is so soft that it can be cut with a knife. It is present in many useful compounds, both natural and artificial. As a metal, it is a very good conductor of electricity and heat. Sodium melts at 98 degrees Celsius (208.4 degrees Fahrenheit) and boils at 883 degrees Celsius (1,621.4 degrees Fahrenheit). It reacts very easily to other substances. For instance, it reacts quickly with water to form sodium hydroxide and hydrogen gas; the heat coming from the reaction burns the hydrogen, forming an open flame.

Salt vs Sodium

So what are the differences between salt and sodium? Following is a breakdown of the areas in which they differ.

Occurrence in nature

Salt, or sodium chloride, can be found throughout nature in places such as the ocean, mineral springs, and inland salt mines. Sodium, on the other hand, cannot be found in its pure state in nature and has to be extracted from its compounds. 

Appearance and Physical Properties

Solid salt is a white, hard crystalline substance that may take on other colors due to impurities. It melts at 801 degrees Celsius and boils at 1,465 degrees Celsius. In contrast, sodium is a soft, silvery-white metal that melts at 98 degrees Celsius and boils at 883 degrees Celsius.

Electricity and Heat Conductivity

Solid salt is a poor electricity and heat conductor. On the other hand, sodium metal conducts heat and electricity very well.

Reactivity with Other Substances

Salt dissolves easily in water; most of the Earth’s water contains salt. Sodium, on the other hand, reacts with water. This reaction forms sodium hydroxide and hydrogen gas, giving the impression that the sodium itself is burning in the water.

Comparison Chart

Salt Sodium
Can be found in nature Has to be extracted from sodium compounds
Hard white crystal Soft silvery-white metal
Melting point: 801 degrees Celsius
Boiling point: 1,465 degrees Celsius
Melting point: 98 degrees Celsius
Boiling point: 883 degrees Celsius
Does not conduct heat or electricity Good heat and electricity conductor
Dissolves in water Reacts with water to form sodium hydroxide and hydrogen gas

Video

Watch the video below for an explanation of the differences between salt and sodium in their respective reactions to water: