Hydrogen fluoride (HF) is a colourless gas or liquid. Potassium oxide (K2O) is a pale yellow solid ionic compound. Let us study their reaction in detail.
Hydrogen fluoride also known as fluorane and hydrofluoric acid is an inorganic compound. It forms corrosive acid upon contact with moisture. Potassium oxide is the simplest oxide of potassium. It is a basic, ionic compound and highly reactive in nature.
This article elaborates on the nature of reaction, enthalpy and a few more aspects of hydrogen fluoride and potassium oxide.
What is the product of HF and K2O
Potassium fluoride (KF) and water (H2O) are formed when hydrogen fluoride (HF) reacts with potassium oxide (K2O).
What type of reaction is HF + K2O
HF + K2O is an acid base reaction i.e. neutralization reaction. It is also a double displacement reaction.
How to balance HF + K2O
The unbalanced equation for the reaction is as follows.
HF + K2O → KF + H2O
To balance the equation, follow the steps given below.
- The number of atoms of all elements before and after the reaction have been tabulated below.
| Compound | Reactant side of equation | Product side of equation |
|---|---|---|
| H | 1 | 2 |
| F | 1 | 1 |
| K | 2 | 1 |
| O | 1 | 1 |
- Here, except for fluorine (F) and oxygen (O), the number of atoms of hydrogen (H) and potassium (K) are not the same on left hand side and right hand side of the equation.
- HF + K2O → KF + H2O
- Now, multiply HF on left hand side of equation with 2 so that number of H atoms on both the sides becomes equal.
- 2HF + K2O → KF + H2O
- Now, the number of H atoms, on left hand side and right hand side are 2 and 2, respectively. Thus, the number of hydrogen atoms is balanced on both sides of the reaction.
- Now, multiply KF on the right hand side of equation with 2 so that the number of K atoms becomes equal on both the sides of the equation.
- 2HF + K2O → 2KF + H2O
- Now, the number of K atoms, on left hand side and right hand side are 2 and 2, respectively. Thus, the number of potassium atoms is balanced on both sides of the reaction.
- Number of atoms of all the elements on both sides of the equation are now balanced.
- Therefore, the balanced equation is as follows.
- 2HF + K2O → 2KF + H2
HF + K2O conjugate pairs
The conjugate pairs of the reaction HF + K2O are as follows.
- Conjugate base of HF: F–
- K2O is the simplest oxide of Potassium, thus there is no conjugate pair.
HF and K2O intermolecular forces
The intermolecular forces acting on HF and K2O are:
- Hydrogen fluoride (HF) has dipole-dipole interactions, hydrogen bonding, London dispersion forces.
- Potassium oxide (K2O) has dipole-dipole interactions, ionic bonding, London dispersion forces.
HF + K2O reaction enthalpy
The net enthalpy of reaction of HF and K2O is -2132.66 kJ/mol. It is calculated from the enthalpy data given in the table below.
| Compounds | Enthalpy (∆Hf°) in kJ/mol |
| HF | (+542) ×2 |
| K2O | -363.17 |
| KF | (-563) ×2 |
| H2O | -285.83 |
| Net enthalpy = -2132.66 |
Reaction Enthalpy = Σ∆Hf°(products) – Σ∆Hf° (reactants)
=[(-563×2) + (-285.83)] – [(-542×2)+(-563×2)]
= -2132.66 kJ/mol
Is HF + K2O a buffer solution
HF + K2O is not a buffer solution, because slight pH changes might destabilise the solution.
Is HF + K2O a complete reaction
HF + K2O is a complete reaction, since reactants are consumed completely to yield products namely potassium fluoride (KF) and water (H2O).
Is HF + K2O an exothermic or endothermic reaction
HF + K2O is an exothermic reaction since the enthalpy of reaction is negative (∆Hf°= -2132.66 kJ/mol) , i.e. temperature of reaction increases.
Is HF + K2O a redox reaction
HF + K2O is not a redox reaction because the oxidation state of elements remains the same throughout the reaction.
Is HF + K2O a precipitation reaction
HF + K2O is not a precipitation reaction, because the product of reaction formed i.e. potassium fluoride is soluble in water.
Is HF + K2O reversible or irreversible reaction
HF + K2O is not a reversible reaction, at ambient conditions, it proceeds in forward direction only, i.e. irreversible reaction.
Is HF + K2O displacement reaction
HF + K2O is a double displacement reaction. Hydrogen reacts with oxygen to form water (H2O), whereas fluorine group reacts with potassium to form potassium fluoride, where oxygen is displaced by fluorine and hydrogen is displaced by potassium.
Conclusion
Hydrogen fluoride and potassium oxide react exothermally to yield potassium fluoride and water. Potassium fluoride found as carobbiite in nature is an alkali halide. It exists in the form of a white coloured powder or crystals.
Hello, I am Ketaki Patil, a chemical engineering undergraduate at the Institute of Chemical Technology. Through Lambdageeks, I am utilizing my writing skills to share knowledge and enable topic understanding in an easy manner.
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