Difference Between Acid and Base (With Table)

Chemicals play a vital role, directly and indirectly, in our life. Acids and Bases are two such forms of chemicals that we come across daily. Both are known as corrosive substances that destroy the other substance that comes in contact with them.

They both hold strong reactive properties and are found everywhere around us for example acid is present in dairy products and lemon in the form of lactic and citric acid, whereas base can be easily found in ammonia and bleach that are used in cleaning.

Due to a few similar chemical properties, it becomes difficult to make out the difference between Acid and Base but can be well differentiated with the help of chemical theories such as Bronsted Lowry theory, Arrhenius theory, and the Lewis theory as well as their chemical properties.

Chemical compounds are categorized with pH values that range from 0 to 14. pH is a measure of the concentration of the hydrogen ions in any chemical solution.

Acid vs Base

The difference between Acid and Base is their pH scale. Acid has a pH scale lesser than neutral (7), whereas base has its scale higher than 7. After dissolving, acid does not change the color of the solution. On the opposite, the base does change. It turns pinkish in coloration. The preceding is the contributor of a proton. On the other side, the succeeding is the recipient of it.


Comparison Table Between Acid and Base (in Tabular Form)

Parameter of ComparisonAcidBase
DefinitionAs per different theories or concepts;As per different theories or concepts;
Arrhenius: Any substances that easily get dissolved in water and increase the concentration of H+ ions is known as Acid.Arrhenius: Any substances that easily get dissolved in water and increase the concentration of OH- ions is known as Base.
Bronsted-Lowry: Acids are the proton donor.Bronsted-Lowry: Bases are the proton acceptor
pH ValueLess than 7.Greater than 7
Chemical FormulaA chemical compound whose formula starts with H is known as Acid. For example, H3BO3 (Boric acid), HCl (Hydrochloric acid). But there exists an exception in the case of CH3COOH (Acetic acid).A chemical compound whose formula ends with OH is known as Base. For example NaOH (Sodium hydroxide), KOH (Potassium hydroxide), etc.
Physical PropertiesAcids are usually sticky, sour in taste, and give a burning sensation. They produce hydrogen gas while reacting with metals.Bases are slippery, odorless, and taste bitter. They easily react with oils and fats.
Litmus Paper Test ResultA blue litmus paper turns red in the case of Acid.A red litmus paper turns blue in the case of Base.
Ion DissociationPositive hydrogen ions (H+) get released when acids dissolved in water.Negative hydroxide ions (OH-) get released when base dissolved in water.
ExamplesSulphuric Acid, Nitric Acid, Acetic Acid, Carbonic Acid, etc.Calcium hydroxide, Sodium Hydroxide, Ammonium hydroxide, etc.


What is Acid?

Any chemical substance that donates protons and accepts electrons are called Acids. The pH level of Acid is less than 7 i.e. hydrogen ions.

Positive hydrogen ions (H+) get released when acids dissolved in water.

As per Arrhenius’s concept, any substances that easily get dissolved in water and increase the concentration of H+ ions is known as Acid.

As per Bronsted-Lowry concept Acids are the proton donor.

Acids are of two types:

  1. Strong Acid: These types of acids completely dissociate ions in water. Examples include Hydrochloric acid (HCL), Chloric acid (HCIO3), Hydroiodic acid (HI), Nitric acid (HNO3), Perchloric acid (HCIO4), Hydrobromic acid (HBr).
  2. Weak Acid: These types of acids partially dissociate ions in water. All acids are of weal type other than six strong acids that are mentioned above.

Characteristics of Acids:

  1. They are electrolytes i.e. acids conduct electricity.
  2. They are sour.
  3. They are corrosive i.e. give a burning sensation.
  4. They are sticky.
  5. They turn the blue litmus paper into the red.
  6. They have low pH value i.e. less than 7.
  7. After reacting with active metals like iron or aluminum, zinc, magnesium they produce hydrogen.

What is Base?

Any substance that accepts protons and donates electrons is called Base. They work just opposite of acids as acids increase the concentration while base decreases the same.

The pH level of the base is higher than 7 and they break apart in water to form negatively charged hydroxide ion (OH-).

As per the Arrhenius concept, any substances that easily get dissolved in water and increase the concentration of OH- ions is known as Base.

As per Bronsted-Lowry, Bases are the proton acceptor.

Bases are of five types

  1. Strong Base: These types of base completely dissociate its ions into the water. Examples are Potassium hydroxide (KOH) and Sodium hydroxide (NaOH).
  2. Weak Base: These bases do not ionize completely or dissociate into water and protonation remains incomplete.
  3. Solid Base: They are used for a reaction or anion exchange with gaseous acids.
  4. Neutral Base: They form a neutral bond with neutral acids.
  5. Super Base: They are formed with conjugate acid by alkali metal. Example include Sodium hydride (NaH)

Characteristics of Bases

  1. They are odorless and bitter.
  2. They have a high pH value i.e. more than 7.
  3. They are slippery.
  4. They turn the red litmus paper into the blue.
  5. Produce water and salt when reacts with acids.

Main Differences Between Acid and Base

To summarize, the main difference between Acid and base are,

  1. Acids donate protons and accept electrons whereas the Base donates electrons and accepts a proton.
  2. Taste of Acid is sour whereas bitter in Base.
  3. Acids have low pH value i.e. less than 7, whereas Base have greater pH value i.e. more than 7 in the range of 0-14.in taste.
  4. Acids are sticky and corrosive whereas Base is soapy and slippery.
  5. Positive hydrogen ions (H+) get released when acids dissolved in water, whereas Negative hydroxide ions (OH-) get released when base dissolved in water.
  6. The chemical formula of Acid starts with H, whereas in case of Base it ends with OH.
  7. In Acid, a blue litmus paper turns red, whereas, in Base, a red litmus paper turns blue.



Acids and Bases can be easily found and are everywhere around us.

The soap we use to shower or to clean utensils, vinegar in the salad, washing powder to wash clothes, in drinks, etc. there are many examples where Acid and Base are present.

But sometimes it becomes a little difficult to differentiate between them due to very close physical and chemical properties that a chemical compound holds.

However, understanding the above-mentioned points can make it easy for anyone.



  1. https://jb.asm.org/content/jb/176/6/1729.full.pdf
  2. https://www.physiology.org/doi/full/10.1152/ajprenal.00115.2003
  3. https://science.sciencemag.org/content/301/5631/349.short
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