Difference Between Salt and Epsom Salt

Main Difference – Salt vs Epsom Salt

Salt is any compound produced from the reaction between an acid and a base. But in general, salt is what we call table salt. It is mainly composed of sodium chloride. It is a white crystalline substance which gives seawater its characteristic taste and is used for seasoning or preserving food. Epsom salt, on the other hand, is hydrated magnesium sulfate. It has a bitter taste. The main difference between salt and Epsom salt is that salt is mainly composed of sodium chloride whereas Epsom salt is hydrated magnesium sulfate.

Key Areas Covered

1. What is Salt
      – Definition, Composition, Production
2. What is Epsom Salt
      – Definition, Composition, Benefits
3. What is the Difference Between Salt and Epsom Salt
      – Comparison of Key Differences

Key Terms: Epsom Salt, Evaporation, Magnesium Sulfate, Salt, Sodium Chloride, Translucent, Transparent

What is Salt

In chemistry, a salt is a chemical compound formed as a result of an acid-base reaction. But in common, salt is a white crystalline substance which gives seawater its characteristic taste and is used for seasoning or preserving food. We call this compound, table salt.

Salt can be obtained either from rock salt ores or from seawater through evaporation. The most common and traditional method of salt production is the evaporation of sea water under direct sunlight. Here, sea water is called brine solution. The brine solution is highly concentrated sea water.

Salt is sodium chloride which is composed of sodium and chloride ions. Therefore, it is an ionic compound.

Table Salt Production Using Brine

The simple and traditional method of table salt production is solar evaporation of brine solution. But this method is suitable only for areas having hot, dry climate. First, the brine is filled into shallow ponds and allowed to evaporate under the sunlight. Here, some heavy impurities such as sand sink to the bottom of the pond. Then the brine is moved to another pond in order to separate seawater from those impurities.

Figure 1: Production of Salt from Sea Water

At the second tank, evaporation is continued. Here, calcium sulfate settles to the bottom of the pond. Once again the brine is moved to a separate pond. Now brine is highly concentrated due to the evaporation of water. In the third pond, highly soluble impurities such as magnesium chloride and magnesium sulfate are removed by pumping brine into a fourth pond before the evaporation is completed. At this final pond, white salt crystals are formed.

These salt crystals are washed with highly concentrated salt water followed by fresh water. This washing is done to remove any impurities on the surface of the salt crystals. Now salt is about 99% pure.

What is Epsom Salt

Epsom salt is hydrated magnesium sulfate. Although this is called a salt, it is actually a mineral of magnesium and sulfate. This compound is composed of seven water molecules per magnesium sulfate molecule. The molecular formula is MgSO₄.7H₂O. The chemical formula is H₁₄MgO₁₁S. It is known as magnesium sulfate heptahydrate.

The name Epsom was given to this salt because of the discovery of this mineral water at Epsom, England. It has many health benefits. Epsom salt appears as large crystals that are colorless. Crystals are translucent or transparent. The crystal system is orthorhombic. The streak is white or colorless (streak of a mineral is the appearance of it when it is finely powdered).

Figure 2: Epsom salt Crystals

Since Epsom salt is easily absorbed via the skin, it is used for salt baths. Some health benefits of Epsom salt includes easing muscle strain, relaxing the nervous system, and drawing toxins out of the body.

Epsom salt can be found as an efflorescent (a precipitation from vapor), limestone cave walls and on the walls of various mineral mines.

Definition

Salt: Salt is a white crystalline substance which gives seawater its characteristic taste.

Epsom Salt: Epsom salt is hydrated magnesium sulfate.

Chemical Composition

Salt: Salt is mainly composed of sodium chloride.

Epsom Salt: Epsom salt is composed of magnesium sulfate.

Production

Salt: Salt can be obtained from rock salt or seawater.

Epsom Salt: Epsom salt can be obtained from chemical processes using mineral ores.

Appearance

Salt: Salt appear as white crystals.

Epsom Salt: Epsom salt appear as colorless crystals.

Transparency

Salt: Salt crystals are not transparent.

Epsom Salt: Epsom salts are either transparent or translucent.

Edibility

Salt: Salt is edible and has a salty taste.

Epsom Salt: Epsom salt is somwehat edible but has a bitter taste.

Conclusion

Both normal salt and Epsom salt have health benefits. Epsom salt has a bitter taste. Normal salt doesn’t have a bitter taste. Salt is consumed as a food additive. The main difference between salt and Epsom salt is that salt is mainly composed of sodium chloride whereas Epsom salt is hydrated magnesium sulfate.

References:

1. “Salt.” How Products Are Made, Available here.
2. “Salt.” Wikipedia, Wikimedia Foundation, 28 Nov. 2017, Available here.
3. “Epsom Salt Uses and Benefits.” Gourmet Sea Salts and Bath Salts from SaltWorks, Inc., America’s Sea Salt Company, Available here.

Image Courtesy:

1. “Salt Farmers – Pak Thale-edit1” By JJ Harrison ([email protected]) (tilt correction). – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Magnesium sulfate” By Chemicalinterest at en.wikipedia – Own work (Public Domain) via Commons Wikimedia