Is Sodium fluoride (NaF) an acid or base or neutral?

Home  > Chemistry Article > NaF acid or base?

is sodium fluoride (naf) an acid or base or salt?

Sodium fluoride appears as a white to greenish solid is an inorganic compound with the chemical formula NaF. It is readily soluble in water and generally corrosive to aluminum. 

In this article, we will discuss Is Sodium fluoride (NaF) is an acid or base or salt? 

So, Is NaF an acid or base? NaF is neither an acid nor base, it is salt in nature as it formed from the neutralization of a strong base(NaOH) with a weak acid(HF), however, NaF is said to be basic salt also, due to the formation of OH radicals when dissolved in aqueous solution.

Name of MoleculeSodium fluoride
Chemical formulaNaF
Molar mass41.988 g/mol
NatureBasic salt
pH value>7

Why NaF can't be acid in nature?

A compound is said to be acid when it is capable of releasing the proton or H+ ion on dissolving in an aqueous solution. According to Arrhenius’s theory of acid ” A compound is said to be acid when added in water, it increases the number of H+ ions in solution.

Since NaF doesn’t contain any hydrogen ion, it is unable to release the proton in an aqueous solution.

So, as per Arrhenius’s theory, an aqueous solution of NaF doesn’t have any property of acidic due to the absence of an H+ ion. Therefore, we can say NaF is not an Arrhenius acid.

is naf acidic or basic salt?

Bronsted-Lowry’s theory for an acid state that ” A compound is said to be acid that donates the proton to other species and make conjugate base”.

Therefore, once again NaF doesn’t have any proton, so obvious it is not able to donate the proton to other species.

Hence, NaF is also not a Bronsted-Lowry acid.

Why NaF is a basic salt?

Have you ever heard what do these terms mean by “Acidic salt”, “Basic salt”, “Neutral salt”, “Amphoteric salt”?

Acidic salt: Acidic salt is formed when a neutralization reaction carries out between strong acid and weak base. This type of salt produces an acidic solution after being dissolved in a solvent that has a pH value of less than 7. Examples of acidic salt – NH4Cl, NH4NO3, NH4Br, etc.

Also Read:-

Basic salt: A basic salt is formed when a neutralization reaction carries out between a strong base and weak acid. This type of salt produces a basic solution after being dissolved in a solvent that has a pH value of more than 7 Example of basic salt – Na2CO3, Soap, NaCN, etc.

Also Read:-

Neutral salt: This salt has a pH value equal to 7 which means it neither has acidic properties nor basic properties. It is formed when a neutralization reaction carries out between a strong acid and strong base or weak acid and weak base. Examples of neutral salt – NaCl, KCl, NaNO3, etc.

Also Read:-

Amphoteric salt: This salt can act as acidic salt as well as a basic salt. Or “Amphoteric means the compound has the ability to act as an acid with a base and base with an acid”. Example of Amphoteric salts – NaHCO3, HCO3, CH3OH, etc.

Also Read:-

Ok, Now come to the point Why does NaF act as basic salt? As we know, Sodium fluoride is formed when NaOH(Strong base) reacts with HF(Weak acid). They react with each other in the molar ratio of 1:1.

⇒ NaOH + HF → NaF + H2O

As per the concepts of salts, a combination of a strong base and weak acid leads to form a basic salt. 

why naf is a basic salt

 

The nature of salt(acidic or basic) is dependent on the strength of the component in the acid-base reaction. 

  • An aqueous solution of stronger acid and weak base will acquire more property of acidic rather than a base.
  • An aqueous solution of a stronger base and weak acid will acquire more property of basic rather than an acid.

In the case of NaF, a stronger base(NaOH) reacts with a weaker acid(HF), so the aqueous solution of its acquires more property of base rather than an acid.

Hence, we can say NaF is a basic salt in nature.

Why the aqueous solution of NaF becomes basic?

An aqueous solution having a pH value of more than 7 is called a basic aqueous solution.

When sodium fluoride is dissolved in an aqueous solution, it will split into two ions Na+ and F.

⇒ NaF → Na+ + F

The Na+ is a cation of strong base(NaOH), hence, it will not undergo hydrolysis in water and doesn’t affect the pH of the solution. But the F is the anion of a weak acid that gets hydrolysis in water to form HF, leaving OH ions that make the solution basic.

⇒ F + H2O → HF + OH

why aqueous solution of naf is basic

A weak acid like HF remains undissociated in an aqueous solution or only partially dissociate, hence, the final solution contains more OH ion than H+ ion. 

Therefore, the presence of additional OH ions in the aqueous solution, sodium fluoride (NaF) solution become basic in nature.

Note: An aqueous solution nature depends on the H+ and OH ions. When more OH ions are present in an aqueous solution, then the solution becomes basic, and when more H+ ions are present in an aqueous solution, the solution becomes acidic.

Also, when the number of H+ and OH ions same in an aqueous solution, then the solution is said to be neutral.

Is NaF considered strong or weak(acidic or basic salt)?

Sodium fluoride is neither acidic nor basic, it is salt made up of a strong base and weak acid. Strong bases dissociate completely in solution and release a larges number of OH ions but the weak acid mostly remain undissociated and release fewer H+ ions.

Therefore, with the presence of more OH ions in an aqueous solution of NaF, we can consider it a strong basic salt.

The concept of acidic salt and basic salt:-

⇒ Strong base + Weak acid = Basic salt     (∴ OH ions > H+ ions)

⇒ Stronger acid + Weak base = Acidic salt     (∴ H+ ions > OH ions)

Uses of Sodium fluoride

  1. It is used as an insecticide, pesticide, and rat poison.
  2. It is used for the manufacture of glasses in various industries.
  3. It is used in the pharmaceuticals industry to prevent dental cavities.
  4. It is also used to fluorinate water supplies.
  5. It is used as a cleansing agent.

Properties of Sodium fluoride

  • It has a boiling point of 1,704 °C and a melting point of 993 °C.
  • It is generally odorless and appears as white to greenish solid.
  • It is slightly soluble in HF, ammonia but insoluble in alcohol, acetone, etc.
  • It has a cubic crystal structure.
  • The molecular shape of NaF is octahedral.
  • It is noncombustible and corrosive to aluminum.

Summary

Sodium fluoride is an inorganic compound also known as florocid has the chemical formula NaF. It is white in color with no odor and highly soluble in water. It is prepared by treating sodium hydroxide with hydrofluoric acid.

  • Is sodium fluoride (NaF) acidic or basic salt? NaF is a basic salt having a pH value of more than 7, made from the neutralization of a strong base(NaOH) with a weak acid(HF).
  • The aqueous solution of sodium fluoride(NaF) is basic in nature due to having more hydroxide ions produced from the hydrolysis of fluoride ions(F + H2O → HF + OH).
  • The presence of fewer hydrogen ions and more OH ions, increases the pH level of the NaF solution.
Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 2 other subscribers

Share it...

Leave a Comment

Your email address will not be published.

© copyright 2021 - topblogtenz.com. All rights Reserved