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

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Hydrofluoric acid is the solution of hydrogen fluoride. Sodium hydroxide is an inorganic compound with the formula NaOH. Let us see the reaction of HF+ NaOH. 

The formula of hydrofluoric acid is HF. It is a colorless, weak acid. HF is commonly used in PTEF (Teflon). NaOH is a strong base, and its molar mass is 39.9971 g/mol.

Here, in this article, we will discuss some facts about the HF+ NaOH reaction, like net ionic reaction and enthalpy of the reaction etc.

What is the product of HF and NaOH

Sodium Fluoride (NaF) and Water (H2O) are produced in the  HF+ NaOH reaction.

NaOH + HF → NaF + H2O

What type of reaction is HF + NaOH

HF+ NaOH is acid-base reaction because, here more than one H exchange is involved and make the reaction neutral.

How to balance HF + NaOH

The reaction HF+ NaOH is balanced using the algebraic method.

  • At first, we labeled all the reactants and the product in the equation with some variables to symbolize the unknown coefficients.
  • a HF + b NaOH = c NaF + d H2O 
  • Then, we do an equation for every element (H, F, Na, O) in which all period represents the range of detail atoms in all reactants and products.
AtomsReactant SideProduct Side
H22
F11
Na11
O11
Molecules Number
  • Now, we see that all atoms on the reactant side and product side are the same. So, we do need any changes in the equation.
  • The balance equation is 
  • NaOH + HF → NaF + H2O

HF + NaOH titration

HF + NaOH is an acid-base titration. This titration has involved some steps.

Apparatus Used:

  • Conical flask
  • Burette
  • Volumetric flask
  • Beakers
  • Measuring cylinders
  • Pipette
  • Glass rod

Indicator:

Procedure:

  • At first, we cleaned the burette and rinsed it with a small amount of NaOH solution, and after that, we filled the burette with the NaOH solution. Record the burette’s initial reading.
  • Then, we pipette out a 25 mL solution of HF into a conical flask.
  • To Determine the endpoint of the reaction, we add a few drops of phenolphthalein indicator into the conical flask.
  • Then, the NaOH solution is added drop by drop using the burette.
  • After that, when the color changes to pink color then, we take the reading of the burette.
  • Then, we determine how much NaOH solution is needed to neutralize the HF solution. 
  • We do this test 3-4 times to get the accurate value.

HF + NaOH net ionic equation

HF+ NaOH net ionic equation is

OH–(aq) + H+(aq) = H2O(l)

To derive the net ionic equation, the following steps are followed

  • Firstly, the soluble ionic compounds dissociate into the ions.
  • Na+(aq) + OH–(aq) + H+(aq) + F–(aq) = Na+(aq) + F–(aq) + H2O(l)
  • Spectator ions is Na+ and F– is canceled out.
  • Thus, the net ionic equation is 
  • OH–(aq) + H+(aq) = H2O(l)

HF + NaOH conjugate pairs

HF + NaOH have conjugate pairs.

  • Conjugate base of HF is F–.
  • Conjugate acid of OH– is H2O.
Conjugate pairs.
Conjugate acid-base pairs

HF + NaOH intermolecular forces

HF And NaOH reaction has the following intermolecular forces:

  • HF has only dipole-dipole interaction force.
  • NaOH has an ion-dipole force.

HF + NaOH Reaction enthalpy

The HF + NaOH reaction has -8.33 kJ/ mol reaction enthalpy.

HF + NaOH buffer solution

HF + NaOH reaction is formed in a buffer solution. We know that to form the buffer solution, we need a weak acid and the conjugate base of the salt.

HF + NaOH complete reaction

HF + NaOH reaction is a complete reaction because the weak acid and the base reacted and formed the salt and water.

Is HF + NaOH an exothermic or endothermic reaction

HF + NaOH is the exothermic reaction because we see from the reaction enthalpy value is negative.

In the below, the energy of the element is mentioned 

ElementEnergy in kJ/ mol
NaOH (aq)470.11
HF (aq)332.36
NaF (s)-569
H2O (g)-241.8
Enthalpy of reaction of individual elements
  • Reactant = 470.11+ 332.36 = 802.47 KJ/mol.
  • Product = – 569 + (-241.8) = – 810.8 KJ/mol.
  • Enthalpy = product – reactant = -810.8 + 802.47 = – 8.33 KJ/mol.

Is HF + NaOH a redox reaction

HF + NaOH reaction is not a redox reaction because there was no change in the oxidation state.

Is HF + NaOH a precipitation reaction

HF + NaOH reaction is not a precipitation reaction because no precipitate is formed in this HF + NaOH reaction.

Is HF + NaOH reversible or irreversible reaction

HF + NaOH reaction is the irreversible reaction because HF + NaOH reaction is formed a complete reaction. 

Is HF + NaOH displacement reaction

HF + NaOH reaction is a double displacement reaction or salt metathesis reaction because Na replaced the H from HF and formed NaF, and H replaced the Na from NaOH and formed H2O.

Conclusion

We can conclude from this article that, HF + NaOH is a double displacement reaction. This is an exothermic reaction, it also released energy.