15 Facts on HF+ LiOH: What, How To Balance & FAQs

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The objective of a chemical reaction is to identify distinct products. Let us examine what this response offers in the reaction of HF + LiOH.

Hydrogen fluoride (HF) is a highly reactive colorless gas with a strong odor. It becomes hydrofluoric acid, a Brǿnsted-Lowry acid when it dissolves in water. Lithium hydroxide (LiOH) is a white, hygroscopic metal hydroxide. This substance behaves as a strong Brǿnsted-Lowry base when dissolved in water.

The article will examine the interaction between HF and LiOH, including its net ionic equation, reaction enthalpy, intermolecular forces, etc.

1. What is the product of HF and LiOH?

HF+ LiOH is combined to create Lithium fluoride (LiF) and water (H2O), respectively.

  • HF + LiOH → LiF + H2O

2. What type of reaction is HF+ LiOH?

HF and LiOH are neutralization reactions, given that salt and water are produced from an acidic and a basic chemical, respectively. Double displacement and precipitation reaction are other categories in which this reaction fits.

3. How to balance HF and LiOH?

HF+ LiOH reaction is balanced in the following steps,

  • Number of atoms must be evenly distributed.
  • Characterize a number of reactants or product species using various factors in order to find the unknown coefficients in the chemical equation (A, B, C, and D).
  • A HF+ B LiOH= C LiF + D H2O
  • Based on stoichiometry, the equation is already balanced, i.e, H= A+B= 2D, F= A=C, Li=B=C, O=B=D
  • As a result, 1 mole of aqueous HF and 1 mole of aqueous LiOH react to produce 1 mole of solid LiF and 1 mole of liquid H2O.
  • The balanced equation is, HF + LiOH = LiF + H2O

4. HF+ LiOH Titration

The titration of HF and LiOH is categorized as acid-base titration. HF is a comparatively weak acid, and LiOH is a strong base. At the equivalence point, the solution would be slightly basic.

Apparatus used

  • Graduated burette
  • Conical flask
  • Volumetric flask
  • dropper
  • Burette stand

Titre and Titrant

  • LiOH is used as the titrant, whose concentration is known.
  • HF is the titre whose concentration is to be analyzed.

Indicator

Phenolpthalein indicator is used in this titration.

Procedure 

  • Samples of weighted HF are thoroughly dissolved in water and measured amount of aqueous HF is placed in a conical flask.
  • Aqueous LiOH solution with known concentration is filled to the burette after washing it.
  • A few drops of penolpthalein are added to the contents of the flask.
  • When the reactants have reacted in exactly equal amounts, and we see a colour change of the solution, this is the equivalence point of the titration.
  • A colorless solution will turn pink at the equivalency point.
  • The sample volume is calculated based on the titration.
  • The stages are repeated a few times to obtain an exact outcome.
  • The equation S1V1 = S2V2 is used to determine the concentration of HF.
  • where S1= concentration of LiOH, V1= volume of LiOH, S2= concentration of HF, V2= volume of HF

5. HF and LiOH Net Ionic Equation

HF+ LiOH reaction gives the following net ionic equation,

HF+ OH– = F– + H2O

To derive this net ionic equation following steps are followed:

  • A balanced form of the general molecular equation is used.
  • HF + LiOH = LiF + H2O.
  • List the chemical state of each compound, such as solid, liquid, gas, or aqueous solution.
  • HF (aq) + LiOH (aq) = LiF (aq) + H2O (l)
  • HF is a weak acid, so it remains as the molecular HF (aq); LiOH gets dissociated into one Li+ (aq) and one OH–(aq) to form Li+ (aq) + F– (aq) + H2O (l) in the reaction system.
  • Write down the net ionic equation after canceling the spectator ions on both sides.
  • The net equation is, HF+ OH– = F– + H2O

6. HF and LiOH Conjugate Pairs

HF + LiOH reaction has the following conjugate pairs,

  • The conjugate base of HF= F–
  • The conjugate acid of LiOH= Li+

7. HF and LiOH Intermolecular Forces

HF + LiOH reaction has the following intermolecular forces,

  • HF molecules exhibit dipole-dipole forces, hydrogen bonding, and dispersion forces.
  • Ionic-dipole forces exist between the molecules of LiOH.    
  • Dipole-dipole interaction and London dispersion forces are the intermolecular forces that hold H2O molecules together.  

8. HF and LiOH Reaction Enthalpy

HF + LiOH reaction enthalpy data is -120.12 kJ/mol. The enthalpy information is as follows:

  • Enthalpy of Formation of HF = -272.72 kJ/mol
  • Enthalpy of Formation of LiOH = -487.46kJ/mol
  • Enthalpy of Formation of LiF= -594.5kJ/mol
  • Enthalpy of Formation of H2O = -285.8 kJ/mol
  • Enthalpy of Reaction = (-594.5-285.8) – (-272.72 -487.46) kJ/mol = -120.12 kJ/mol.

9. Is HF and LiOH Buffer Solution?

HF+ LiOH is a buffer solution because the acid HF is weak. If there is an equal quantity of HF and LiOH present, their neutralization creates the conjugate base of HF, F–. HF and an F– will create a buffer solution inside the system.

10. Is HF and LiOH Complete Reaction?

HF + LiOH reaction is complete since all of the reactant’s moles are entirely transformed and consumed by the product at equilibrium.

11. Is HF and LiOH an Exothermic Reaction?

HF + LiOH reaction is exothermic due to the breakdown of bonds. HF and LiOH generate a lot of heat.

12. Is HF and LiOH a Redox Reaction?

The HF+LiOH reaction is not a redox since the oxidation states of the atoms have not changed.

13. Is HF and LiOH a Precipitation Reaction?

HF +LiOH reaction is a precipitation reaction as the product LiF is the white precipitation formed in the reaction. 

14. Is HF and LiOH a Reversible Reaction?

HF + LiOH reaction is an irreversible reaction. LiF cannot dissolve in water. As a result, under identical circumstances, the products no longer undertake reverse reactions to generate reactants.

15. Is HF and LiOH a Displacement Reaction?

HF + LiOH reaction is a double displacement reaction as both sets of ions get replaced on the product side. H+ ions displace Li+ ions in the base and form H2O. OH– ions displace F– and LiF is formed.

Screenshot 2022 12 16 130058
Double displacement reaction

Conclusion

HF+LiOH reaction is a weak acid-strong base reaction. HF is used to produce fluorocarbons. On the other hand, LiOH is mostly used to make cathode materials.