Press ESC to close

Is NaOH a strong base? Justify.

Did you know that sodium hydroxide (NaOH) is a super strong base? It’s also called caustic soda and it’s used in lots of different industries. When you mix it with water, it breaks apart really quickly and releases hydroxide ions (OH-). It’s really good at being a strong base.

Before discussing is NaOH a strong base or not let’s have a look at basic properties or general information about caustic soda (NaOH). It is also called metal hydroxide or caustic soda.

As it is an ionic compound, easily dissolves in water because it is the dielectric property of water to overcome the ionic bond and dissolve NaOH in water. We can also obtain caustic soda by the electrolysis of brine solution.

NaOH a strong base or not can easily be understood by knowing a basic difference between a strong and weak base. Strength of base can be categorized on the basis of dissociation in an aqueous medium & gaining of a proton or lone pair. The following table will show a great difference between a strong and weak base.

Characteristics of Sodium Hydroxide (NaOH)

Sodium hydroxide, commonly known as NaOH, possesses several distinctive characteristics that make it a strong base. Let’s delve into these properties and understand why NaOH is considered a potent alkaline compound.

Odorless White Solid

NaOH appears as an odorless white solid with a crystalline structure. Its colorlessness and lack of smell make it versatile for various applications. Whether used in manufacturing or laboratory settings, the absence of any distinct odor ensures that NaOH does not interfere with the desired outcomes of experiments or products.

High Melting Point

With an impressive melting point of 318 degrees Celsius, NaOH can withstand high temperatures without losing its chemical properties.

This characteristic makes it suitable for numerous industrial processes that require elevated temperatures. From soap making to metal refining, NaOH’s high melting point allows it to endure extreme heat while fulfilling its intended purpose effectively.

Strong Alkalinity in Aqueous Solution

When dissolved in water, NaOH exhibits remarkable solubility and forms strongly alkaline solutions. The hydroxide ions (OH-) released during the dissolution process contribute to this intense alkalinity. As a result, these solutions have a high pH value and exhibit corrosive properties.

The complete ionization of NaOH in water is represented by the following equation:

This equation signifies that when sodium hydroxide dissolves in water, it breaks down into sodium cations (Na+) and hydroxide anions (OH-). The presence of abundant hydroxide ions contributes to the solution’s strong basic nature.

Importance of Hydroxide Ions

Hydroxide ions play a crucial role in determining the strength of a base. In the case of sodium hydroxide, the release of hydroxide ions upon dissolution gives rise to its strong basic properties. These hydroxide ions can react with acidic substances, neutralizing them and forming water molecules.

Difference b/w a Strong and weak base

1. A strong base is the base that split up completely 100 % into its ions in an aqueous medium.1. A weak base is a base that does not split up 100% completely into its ions in an aqueous medium.
2. It has a pH of more than 7 but less than 14.2. It has a pH relatively close to 7. i.e, 8 or 7.9, etc.
3. Strong bases have a higher value of Kb (Dissociation constant for bases)3. Weak bases have a lower value of Kb.
4. No reversible reaction occurs due to complete ionization or dissociation.4. A reversible reaction occurs due to incomplete dissociation.
Table representing the difference between strong or weak base.

Acid-Base concepts to show NaOH a strong base

There are following three valid concepts that can show you that Is NaOH a strong base or a weak base. These concepts are the Arrhenius concept, Lowry-Bronsted concept, and Lewis concept.

1. Arrhenius’s concept

This concept is only valid in an aqueous medium. So, if we talk about base. That base is said to be a strong base if it will give OH ions in water at dissociation. According to Arrhenius’s concept “THAT BASE WILL BE VERY STRONG BASE WHICH gives OH ion AT DISSOCIATION“. So, NaOH is a strong base because it will dissociate completely and also give OH ions.

NaOH + H2O → Na+ + OH

So, this theory proves that NaOH is a strong base.

2. Lowry-Bronsted Concept

According to the Lowry-Bronsted concept, a strong base is a substance that can accept a proton. So, when NaOH reacts with the HCl, NaOH accepts a proton from HCl and behaves as a strong base.

NaOH is a strong base due to the presence of OH ions having lone pair. The proton is accepted by the OH ions and in return, OH also shares its electron with hydrogen so that both become stable.

NaOH a strong base

3. Lewis Theory

G. N Lewis proposed a theory representing a brief difference between a strong acid and a strong base. A strong base is a specie that can donate a pair of electrons. When NaOH is dissociated OH ion is separated which means that it is an electron enriched specie.

So, OH in NaOH gives the pair of electrons to the other electron-deficient species so acts as a strong Lewis base.


All the above theories explained proves that NaOH is considered a strong base. The strength of the base is determined by the degree of dissociation. More degree of dissociation results in a strong base. It also depends upon the gaining of a proton or the donation of an electron pair to any other electron-deficient specie.

Applications and Uses of Sodium Hydroxide

Soap makingSodium hydroxide is used in the saponification process to convert fats and oils into soap.
Paper manufacturingSodium hydroxide is used to break down wood fibers in the pulping process, allowing for the production of paper.
Textile industrySodium hydroxide is used to treat and remove impurities from fabrics and fibers.
Water treatmentSodium hydroxide is used to adjust the pH levels in water and neutralize acidic substances.
Food processingSodium hydroxide is used to peel fruits and vegetables, as well as in the production of cocoa and chocolate.
Petroleum industrySodium hydroxide is used to remove impurities from petroleum products through a process called caustic washing.
Cleaning productsSodium hydroxide is a common ingredient in many cleaning products, such as drain cleaners and oven cleaners.
Metal processingSodium hydroxide is used to remove rust and scale from metal surfaces.
PharmaceuticalsSodium hydroxide is used in the manufacturing of various pharmaceutical products.
Biodiesel productionSodium hydroxide is used in the transesterification process to convert vegetable oils into biodiesel.

Why NaOH is not considered acid??

NaOH is not considered acid because it is a property of acids to dissociate a proton in an aqueous medium but NaOH did not possess any proton in it. So, it cannot release an H+ ion. Also, it will not satisfy the conditions of the above-explained theories.


Can I use NaOH for unclogging drains?

Yes, NaOH can be used to unclog drains because it reacts with fats, oils, and other substances that cause blockages. However, it is important to follow safety guidelines when handling NaOH and ensure proper dilution before use.

Is NaOH safe for personal care products?

NaOH is commonly used in the production of personal care products like soaps and shampoos. However, when used directly on the skin or hair without proper formulation by professionals, it can cause irritation or burns. It is best to use products containing NaOH according to the instructions provided.

Can I use NaOH for cooking?

No, using pure NaOH for cooking purposes is not recommended. While food-grade versions of sodium hydroxide exist (such as lye), they should only be used following specific recipes and guidelines provided by reputable sources.

Does using stronger bases provide better results than using NaOH?

The choice between using stronger bases or NaOH depends on the specific application requirements. In many cases, NaOH’s strength is sufficient for desired results, and using stronger bases may be unnecessary or even detrimental. It is important to consider factors such as safety, cost-effectiveness, and compatibility with other substances.

How should I store NaOH?

NaOH should be stored in a cool, dry place away from moisture and incompatible materials. It should be kept in a tightly sealed container to prevent absorption of carbon dioxide from the air, which can weaken its effectiveness over time. Always ensure proper labeling and keep it out of reach of children or unauthorized individuals.

Leave a Reply

Your email address will not be published. Required fields are marked *

@Katen on Instagram
[instagram-feed feed=1]