Na2CO3 is often known as soda ash or washing soda. It is a non-volatile base. HF is an ionic, polar weak acid with a dipole moment of 1.86 D. Let us see how Na2CO3 reacts with HF.
Na2CO3 is a water – soluble white solid and a sodium salt of carbonic acid. Its major source is trona ore. It is used in soaps, paper, water glass, and acts as a water softener and base. HF is linear with a point group C∞v. Its 60 % is used to make the refrigerants. French chemist Edmond Frémy is credited with the HF.
In this article, we will discuss important facts about HF + Na2CO3 chemical reactions such as reaction enthalpy, the heat required, the product formed, the type of reaction, the type of intermolecular forces between their compounds, etc.
What is the product of HF and Na2CO3
Sodium fluoride (NaF), carbon dioxide (CO2), and water (H2O) is produced during the reaction of HF and Na2CO3 where Sodium fluoride is dissolved in water.
2 HF (aq) + Na2CO3 (s) = 2 NaF (aq) + H2O (l) + CO2 (g)
What type of reaction is HF +Na2CO3
HF + Na2CO3 is double displacement (salt metathesis), acid – base (neutralization), and an exothermic reaction.
How to balance HF +Na2CO3
The unbalanced molecular equation for HF + Na2CO3 is.
HF (aq) + Na2CO3 (s) = NaF (aq) + H2O (l) + CO2 (g)
To balance this equation, we should follow the steps given below:
- Here, the number of H and Na atoms is not the same on both sides of the reaction. So we will multiply these atoms with some coefficients so that they become equal.
- The total number of H atoms on the reactant side is 1 while on the product side it is 2.
- So, we multiply the HF with a coefficient of 2 on the reactant side so that the number of H atoms becomes 2 on both sides of the reaction.
- 2 HF (aq) + Na2CO3 (s) = NaF (aq) + H2O (l) + CO2 (g)
- Similarly, 2 Na atoms are present on the reactant side while it is 1 on the product side of the reaction.
- So, we multiply the NaF with a coefficient of 2 on the product side so that the number of Na atoms becomes 2 on both sides of the reaction.
- HF (aq) + Na2CO3 (s) = 2 NaF (aq) + H2O (l) + CO2 (g)
- Finally, the balanced equation is:
- 2 HF (aq) + Na2CO3 (s) = 2 NaF (aq) + H2O (l) + CO2 (g)
HF + Na2CO3 titration
Quantitative estimation of hydrogen fluoride is estimated by performing the titration of HF against a standard solution of Sodium Carbonate.
Apparatus used
A burette, Pipette, measuring flask, glass funnel, clamp stand, measuring cylinder, volumetric flask, and beakers are required for this titration.
Indicator
The methyl orange indicator is used for this titration.
Procedure
- A standard amount of Na2CO3 is filled into the burette and noted the initial reading on the burette.
- At the same time, the aqueous solution of HF with the respective indicator methyl orange is taken in a conical flask.
- Then Na2CO3 is added dropwise into the conical flask very carefully till the color changes to light pink.
- The constant shaking of the conical flask provides an accurate endpoint. Now note the final reading at the burette.
- The procedure is repeated at least three times until a constant endpoint comes where the indicator changes its color.
- After the successful titration, the strength of hydrogen fluoride is measured by the formula V1N1 = V2N2.
HF +Na2CO3 net ionic equation
The net ionic equation of HF + Na2CO3 is as follows:
2H+(aq) + Na2CO3 (s) = 2 Na2+ (aq) +H2O (l) + CO2 (g)
To get the net ionic equation for HF +Na2CO3, we should follow the steps given below:
- Write the general balanced molecular equation.
- 2 HF + Na2CO3 = 2 NaF + H2O + CO2
- Now the solubility equation for HF + Na2CO3 is written by labeling the state or phase (s, l, g or aq) of each substance in the balanced molecular equation of HF + Na2CO3.
- 2 HF (aq) + Na2CO3 (s) = 2 NaF (aq) + H2O (l) + CO2 (g)
- Break all aquatic soluble ionic substances into their corresponding ions to get the balanced ionic equation.
- 2H+ (aq) +2F– (aq) + Na2CO3 (s) = 2 Na2+ (aq) + 2F− (aq) +H2O (l) + CO2 (g)
- To get the net ionic equation, remove spectator ions (F– ) from the reactant and product side of the balanced ionic equation.
- Finally, the net ionic equation for HF + Na2CO3 is:
- 2H+(aq) + Na2CO3 (s) = 2 Na2+ (aq) +H2O (l) + CO2 (g)
HF + Na2CO3 conjugate pairs
The conjugate pairs (compounds differ by one proton in their respective pair) in HF + Na2CO3 are:
- The conjugate base of HF acid is F–.
- The conjugate base of H2O is OH–.
- Na2CO3, NaF, and CO2 do not have their conjugate pairs because these compounds do not contain hydrogen atoms that can remove as proton ions.
HF and Na2CO3 intermolecular forces
The intermolecular forces that work on HF and Na2CO3 are-
- Dipole-dipole force, London dispersion force, and hydrogen bonding are present in HF molecules.
- The electrostatic force of attraction and Coulomb force is present in Na2CO3 molecules that held Na+ ion to CO32- ions.
- The electrostatic force of attraction and Coulomb force is present in NaF as it is a strong ionic compound.
- Hydrogen bonds, dipole-induced dipole forces, and London dispersion forces exist in water due to their strong polar and ionic nature.
- London dispersion force is the only intermolecular force that is found in the CO2 molecules because of its extremely low boiling point ( -78.46 °C).
HF + Na2CO3 reaction enthalpy
The net enthalpy change of the reaction HF + Na2CO3 is -28.60 kJ/mol. The value is gained from the following mathematical calculation.
Compound | Standard Formation Enthalpy (ΔfH°(Kj/mol)) |
HF | -255.64 |
Na2CO3 | -1130.94 |
NaF | -495.74 |
H2O | -285.83 |
CO2 | -393.51 |
- ΔH°f = ΣΔH°f (products) – ΣΔH°f (reactants) (kJ/mol)
- ΔHf = [2*( -495.74) +(-285.83) +(-393.51) -(2* (-255.64) +(-1130.94)] kJ/mol
- ΔHf = -28.60 kJ/mol
Is HF +Na2CO3 a buffer solution
HF + Na2CO3 is not a buffer solution because this mixture does not contain the corresponding weak acid (i.e. H2CO3) of Na2CO3 salt.
Is HF + Na2CO3 a complete reaction
HF + Na2CO3 is a complete reaction because in this reaction HF and Na2CO3 are completely consumed and converted into the final product (NaF) successfully.
Is HF + Na2CO3 an exothermic or endothermic reaction
HF+Na2CO3 reaction is an exothermic reaction because the net change of enthalpy is negative (i.e., ΔHf < 0, -28.60 kJ/mol) where the -ve sign interprets the following facts about the reaction:
- 28.60 kJ/mol heat is released by the reactants HF and Na2CO3 due to the formation of less energetic salt NaF.
- Heat emission by HF and Na2CO3 rises the energy of surroundings and makes the products stable.
Is HF +Na2CO3 a redox reaction
HF +Na2CO3 is not a redox reaction as we see the oxidation number of all atoms H, F, Na, C, and O are all the same in reactants and products as well.
Is HF + Na2CO3 a precipitation reaction
HF+ Na2CO3 is not a precipitation reaction because the completion of the reaction provides the NaF as the main product that is dissolved in reaction media.
Is HF + Na2CO3 reversible or irreversible reaction
HF + Na2CO3 is an irreversible reaction because the product NaF and CO2 are stable so they do not need to react with each other to form reactants back.
Is HF +Na2CO3 displacement reaction
HF + Na2CO3 is a double displacement reaction because, in this reaction, fluoride ion (F–) and carbonate ion (CO32- ) exchange their places with each other to form new products, NaF, H2O, and CO2.
Conclusion
HF + Na2CO3 reaction is carried out through a double displacement reaction in which sodium fluoride and carbonic acid (H2CO3) are formed and because carbonic acid is less stable it breaks down into H2O and carbon dioxide (CO2). During the whole reaction, net 28. 60 kJ/mol energy is released by reactants.
Hi, I am Kavita Singhal, Ph.D. in Chemical Sciences. My subject area of interest is Physical and Inorganic Chemistry with special emphasis on Electrochemistry, Polymer Chemistry, Nano Chemistry, Corrosion Study, Cyclic voltammetry, Supercapacitance, and Organometallic Chemistry.
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