Hydrofluoric acid is a weak acid whereas Barium hydroxide is strong base. Let us now discuss the reaction: HF + Ba(OH)2.
Hydrogen fluoride(HF) is a colourless, acidic and highly corrosive solution. It is a weak acid that does not completely dissociates in water. Barium hydroxide [Ba(OH)2] is a white granular monohydrate also called as baryta. It acts as a strong base. This is used to dehydrate and extract sulfate from different products.
In the following article, we will discuss the reaction’s products, method of balancing, ionic equation, intermolecular forces, reaction enthalpy, and few more facts about the reaction between HF and Ba(OH)2.
What is the product of HF and Ba(OH)2?
Barium fluoride is obtained as a precipitate along with water by the reaction HF + Ba(OH)2.
HF + Ba(OH)2 = H2O + BaF2.
What type of reaction is HF + Ba(OH)2?
The reaction between HF and Ba(OH)2 is an acid-base neutralization reaction where, HF is a weak acid and Ba(OH)2 is a strong base.
How to balance HF + Ba(OH)2?
The reaction HF + Ba(OH)2 = H2O + BaF2 is not balanced yet. We have to balance the given equation in the following way:
- The reactants and the products are labeled by a, b, c, d and e variables to represent the unknown coefficients.
- aHF + bBa(OH)2 = cH2O + dBaF2
- The same type of elements is rearranged together, and then the coefficients are equated.
- After rearranging by their stoichiometric proportion, we get
- H=a=2b=2c; F=a=2d;Ba=b=d; O=2b=c
- Now we use the Gaussian elimination method to determine the values of the coefficients
- We get a=2 , b=1 ,c=2 , d=1
- Hence the overall balanced equation is:
- 2HF + Ba(OH)2 = 2H2O + BaF2
HF + Ba(OH)2 titration
The titration for the reaction of HF + Ba(OH)2 is an acid-base titration.The process of titration is discussed below-
Apparatus Used
Beakers, a wash bottle, a stirrer, a pipette, distilled water, a conical flask, a volumetric flask, and a pipette.
Indicator
In this titration, Phenolphthalein indicator is used to detect the end point of the titration.
Procedure
- Hydrofluoric acid, is taken in the conical flask and is then titrated with the strong base Ba(OH)2.
- 1 or 2 drops of phenolphthalein is then added to it.
- It is then titrated with a known concentration of the strong base Ba(OH)2. After that solution of Ba(OH)2 is added to the solution of HF drop wisely until the solution turns pink and the endpoint is determined.
- After that we note down the volume required to neutralize the HF acid solution.
- The above steps are repeated three times until three consistent readings are made.
- After this we use the formula S1V1=S2V2, where S1 and V1 are the strength and volume of Ba(OH)2 and S2 and V2 are the strength and volume of HF. Thus using this we can calculate the value of strength of HF.
HF + Ba(OH)2 net ionic equation
The net ionic equation of the reaction of HF + Ba(OH)2 is –
2H+ + 2F– + Ba2+ + 2OH– = 2H2O+ BaF2
To derive the net ionic equation following steps are used.
- Firstly the chemical states are indicated in the equation:
2HF (aq.) + Ba(OH)2 (aq.) = 2H2O(l) + BaF2 (s) - Then the corresponding compounds are split into their ionic forms as follows:
- 2H+(aq) + 2F–(aq) + Ba2+(aq) + 2OH–(aq) = 2H2O(l) + BaF2(s)
- Thus, the net ionic equation is:
- 2H+ + 2F– + Ba2+ + 2OH– = 2H2O+ BaF2
HF + Ba(OH)2 conjugate pairs
The conjugate pairs of HF + Ba(OH)2 are-
- The conjugate base for HF is F– .
- The conjugate acid for Ba(OH)2 is Ba2+.
HF and Ba(OH)2 intermolecular forces
HF and Ba(OH)2 has the following intermolecular forces:
- A strong dipole-dipole interaction exist between the ions of HF molecule, because it is a polar molecule.
- There an ionic bond exists in case of Ba(OH)2 molecule.
HF + Ba(OH)2 reaction enthalpy
HF + Ba(OH)2 reaction enthalpy is -470.32 KJ/mol.
The formula for enthalpy calculation is= Enthalpy of Product – Enthalpy of Reactant
- = [-1207.1+2x(-285.83)]-[2x(-332.36)+(-643.9)] KJ/mol
- = -470.32 KJ/mol
| MOLECULE | ENTHALPY (KJ/MOL) |
|---|---|
| HF | -332.36 |
| Ba(OH)2 | -643.9 |
| BaF2 | -1207.1 |
| H2O | -285.83 |
Is HF + Ba(OH)2 a buffer solution?
HF + Ba(OH)2 is not a buffer solution because of the presence of a strong base i.e, Barium Hydroxide.
Is HF + Ba(OH)2 a complete reaction?
HF + Ba(OH)2 is a complete reaction because at the end of the reaction white crystals of BaF2 is obtained.
Is HF + Ba(OH)2 an exothermic or endothermic reaction?
HF + Ba(OH)2 is an exothermic reaction because of the negative enthalpy value obtained during the reaction.
Is HF + Ba(OH)2 a redox reaction?
HF + Ba(OH)2 is not a redox reaction because the oxidation states of the elements remain unchanged during the reaction.
Is HF + Ba(OH)2 a precipitation reaction?
HF + Ba(OH)2 is a precipitation reaction as white crystalline BaF2 is precipitated out at the end of this reaction.
Is HF + Ba(OH)2 reversible or irreversible reaction?
HF + Ba(OH)2 is an irreversible reaction where BaF2 is precipitated out which is insoluble in water.
Is HF + Ba(OH)2 displacement reaction?
HF + Ba(OH)2 is a double displacement reaction. In this reaction, F of HF is is replaced by OH from Ba(OH)2 and OH of Ba(OH)2 is replaced by F from HF.
Conclusion
The reaction between a weak acid HF and strong base Ba(OH)2 is a acid-base neutralization reaction that forms Barium fluoride as a salt along with water.
Hello… , I am Bhaswati Ghose. I have completed my master’s from St. Xavier’s College, Ranchi. My specialization subject was organic chemistry. I’m working as a subject matter expert in chemistry.