# Preparation, Properties and Uses of Sodium Chloride - Introduction, Physical Properties, Chemical Properties, Practice Problems, FAQs

Raj, a 12th-class student, has a younger sister Mala who is 7 years old. She is very intelligent and always willing to ask questions to her parents, friends and teachers. Sometimes they answer her questions but sometimes they fail. As we all know a child’s mind can ask beyond limits! One day there were some guests who arrived at their house, and then their mother served them so many snacks. Some of them were also given to both Raj and Mala. You all are very curious to know why I am telling you this story.

The main crunch here is while eating snacks, mala asked his brother that bhaiya why all snacks have one common taste, they are salty. What is the major ingredient used in all of them in common? Raj thought for a few seconds then he explained that every snack she is having contains some amount of salt which is giving a common salty taste to all these items.

Yes, salt is very important and there is a very famous historical story related to this. Mahatma Gandhi started the Salt Satyagraha, a large-scale civil disobedience movement, in response to the salt tax, the British government had implemented on the Indian people. Gandhi ji wants no tax on salt as it was the basic important need for a human to consume food and should be accessible to all.

Thinking about the importance of salt in history, it also has great importance in chemistry also. In chemistry, this important salt is known as Sodium chloride.

Let us study this important compound and its physical and chemical properties in a bit more detail!

TABLE OF CONTENT

• What is Sodium Chloride?
• Occurrence of NaCl
• Structure of Sodium Chloride
• Physical Properties of Sodium Chloride
• Preparation of Sodium Chloride
• Chemical properties of Sodium Chloride
• Uses of NaCl
• Practice Problems

## What is sodium chloride?

The sodium and chloride ions that make table salt, halite, or common salt have a 1:1 ionic composition. The chemical name for table salt is Sodium Chloride and the chemical formula is NaCl. The saltiness of saltwater is due to sodium chloride, or NaCl. Extracellular fluid, which is found in multicellular organisms, also contains it. Common salt, or NaCl, can be found in large quantities in marine water.

Salt is referred to chemically as sodium chloride. An electrolyte called sodium controls how much water is in your body. Muscle contractions and nerve impulses are both influenced by sodium.

To treat or prevent sodium loss brought on by dehydration, excessive sweating, or other factors, sodium chloride is utilized.

## Occurrence of NaCl:

Typically, salts are the source of all the substances that make up either sodium or chlorine. Because of this, it is abundant in nature. The majority of the dissolved components in seawater are made up of salt.

The mineral halite is one way we can obtain pure salt. Since the saline solution can produce sodium chloride or NaCl solutions, it makes it simple to mine the deposits. As a result, transporting the mineral through water from deposits is frequently done. Consequently, the salts dissolve, and the solution is then pumped away.

One of the most popular processes for producing salt is saltwater evaporation, which is employed in many nations, including India. However, the salt that is obtained in crystals frequently contains contaminants like calcium and sodium sulphates, among others. When obtaining a pure sodium chloride crystal, it is necessary to first dissolve the crystals in water before filtering the solution.

## Structure of Sodium Chloride:

NaCl has a face-centred cubic crystalline structure and a cubic crystal system. Four cations and four anions make up a face-centred cubic unit cell of sodium chloride. Since each unit cell of a face-centred cubic structure contains 4 atoms or ions, there are 4 NaCl units in a unit cell of NaCl.

The radius ratio for sodium chloride, NaCl, is 0.52, which points to an octahedral configuration. In the corners of a normal octahedron, each Na+ ion is surrounded by six Cl- ions, and the opposite is true for each Cl- ion. Thus, the coordination is 6: 6. This structure can be thought of as a cubic, tightly packed array of Cl- ions, with Na+ ions filling up every hole in the octahedron.

The energy required when one mole of a molecule is generated from its gaseous ions is known as the lattice energy (U) of a crystal:

## Physical properties of Sodium Chloride:

• It is a crystalline white substance. It has some hygroscopicity.
• When pure, it has a density of 2.17 g/mL. At 800°, it melts down.
• It is water soluble. With the help of heat absorption, it dissolves in water.
• It is insoluble in alcohol.
• The extraction of sodium and production of all other sodium compounds begins with the common salt. Common salt is primarily utilized to obtain sodium, sodium hydroxide, and sodium carbonate, which are subsequently used to create other significant sodium compounds.

## Preparation of Sodium Chloride:

A common chemical known as sodium chloride usually referred to as table salt, common salt, or simply NaCl, can be created in laboratories by combining sodium with chlorine.

The reaction is as follows:

## Chemical properties of Sodium Chloride:

NaCl as electrolyte:

NaCl is formed when an acid and an alkali react. Sodium chloride is a strong electrolyte. Generally, ions are very strongly attracted to one another, and only polar solvents can break the attraction between them. The crystal lattice easily disintegrates in water. The bond's cation and anion (Na+, Cl- ) are released. This explains why sodium chloride has strong electrical conductivity.

Chlor-alkali process:

According to the chemical equation, it serves as the starting point for the chloralkali process, an industrial method for producing chlorine and sodium hydroxide.

Either a mercury cell, a diaphragm cell, or a membrane cell is used to carry out this electrolysis. The chlorine is separated from the sodium hydroxide in each of those processes using a different technique. Due to the high energy consumption of electrolysis, other methods are being developed, where even slight increases in efficiency can result in significant financial gains. Production of PVC thermoplastics, disinfectants, and solvents are a few uses for chlorine.

Numerous industries, including those that enable the production of paper, soap, and aluminium, among others, use sodium hydroxide extensively.

Solvay process:

In the industrial Solvay process, limestone (CaCO3) is used to create carbon dioxide (CO2), which then interacts with ammonia (NH3) dissolved in concentrated sodium chloride (NaCl(aq)) to create sodium carbonates.

$2NaCl+CaC{O}_{3}\to {Na}_{2}{CO}_{3}+Ca{Cl}_{2}$

## Uses of NaCl:

• There are various uses for sodium chloride, often known as NaCl, used in the food business because it may be added to food to improve the flavour as well as be used as a preservative in a variety of food products.
• Sodium chloride is a crucial raw ingredient in the manufacturing of sodium hydrogen carbonate, sodium carbonate, etc.
• NaCl, often known as sodium chloride, can be used to make glass.

## Practice Problems:

Q1. The nature of sodium chloride is ______________.

A. deliquescent
B. alkaline
C. basic
D. acidic

Solution: Delinquency has a propensity to dissolve. Sea water is evaporated to produce sodium chloride, however, because of impurities like calcium chloride and magnesium chloride, it has a deliquescent character.

Q2. If the amount of NaOH is doubled and there is an excess of HCl present, the number of moles of NaCl will be___________.

A. Half
B. Doubled
C. Four times
D. None of the mentioned

Solution: NaOH will be the limiting reagent because it is present in a lesser quantity. NaCl is created from 1 mol of NaOH. Equal to 1 mole of NaOH and 1 mole of HCl. If we take 2 moles of NaOH , then it is obvious that NaCl formed will be 2 moles, i.e doubled.

Here is the mentioned reaction,

Q3. Pure NaCl precipitates as a result of the ______________.

A. common Ion effect
B. common electron effect
C. common cation effect
D. common Proton effect

Solution: From passing HCl gas through the impure saturated solution of sodium chloride, which is acquired by the evaporation of seawater, pure sodium chloride is precipitated, yielding 28% of the saturated sodium chloride solution, which is known as brine.

Q4. What is the name of the saturated NaCl solution?

A. Soda water
B. Slaked lime
C. Brine
D. Lime water

Solution: A salt solution in water, or sodium chloride solution, is called brine. Brine can refer to salty liquids with concentrations ranging from 3.5% to roughly 26%. (a typical saturated solution, depending on temperature).

1. Is NaCl an electrical conductor?
Because there are no free electrons in solid sodium chloride, it does not conduct electricity. Because of the mobility and discharge of the ions during electrolysis, sodium chloride melts and conducts electricity.

2. What follows when heated NaCl?
Because of a metal excess defect in the sodium chloride crystal when heated with sodium vapors, sodium chloride takes on a yellow colour. It appears yellow because of an electrical transition at the excited state of the sodium atom.

3. Where in daily life do we utilize NaCl?
In order to keep patients from dehydrating, sodium chloride, an essential nutrient, is employed in healthcare. It is employed as a spice to improve flavour and as a food preservative. Additionally, sodium chloride is employed in producing polymers and other goods. Additionally, it is used to de-ice sidewalks and roads.

4. What pH of sodium chloride is?
pH of sodium chloride solutions is equal to 7 . The pH of a sodium chloride solution remains ≈7 due to the extremely weak basicity of the Cl- ion, which is the conjugate base of the strong acid HCl.