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Chemical reactions
KF + HIO3 → KIO3 + HF↑

KF + HIO₃ → KIO₃ + HF↑

Last updated: June 13, 2022

Reaction of potassium fluoride and iodic acid: KFPotassium fluoride + HIO₃Iodic acid
⟶
KIO₃Potassium iodate + HF↑Hydrogen fluoride

The reaction of potassium fluoride and iodic acid yields potassium iodate and hydrogen fluoride. This reaction is an acid-base reaction and is classified as follows:

Table of contents

Reaction data

Reactants

Chemical formula	Name	Coefficient	Type	Type in general equation
KF	Potassium fluoride	1	Brønsted base	Salt of weak acid Salt of volatile acid
HIO₃	Iodic acid	1	Brønsted acid	Strong acid Nonvolatile acid

Products

Chemical formula	Name	Coefficient	Type	Type in general equation
KIO₃	Potassium iodate	1	Conjugate base	Salt of strong acid Salt of non volatile acid
HF	Hydrogen fluoride	1	Conjugate acid	Weak acid Volatile acid

Thermodynamic changes

Changes in standard condition

Reaction of potassium fluoride and iodic acid: KFCrystalline solid + HIO₃Crystalline solid
⟶
KIO₃Crystalline solid + HF↑Gas

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	24.9	–	–	–
per 1 mol of Potassium fluoride	24.9	–	–	–
per 1 mol of Iodic acid	24.9	–	–	–
per 1 mol of Potassium iodate	24.9	–	–	–
per 1 mol of Hydrogen fluoride	24.9	–	–	–

Changes in aqueous solution (1)

Reaction of potassium fluoride and iodic acid ◆ Δ_rG 10.3 kJ/mol K 0.16 × 10⁻¹ pK 1.80: KFIonized aqueous solution + HIO₃Un-ionized aqueous solution
⟶
KIO₃Ionized aqueous solution + HF↑Gas

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	51.6	10.3	139.1	–
per 1 mol of Potassium fluoride	51.6	10.3	139.1	–
per 1 mol of Iodic acid	51.6	10.3	139.1	–
per 1 mol of Potassium iodate	51.6	10.3	139.1	–
per 1 mol of Hydrogen fluoride	51.6	10.3	139.1	–

Changes in aqueous solution (2)

Reaction of potassium fluoride and iodic acid ◆ Δ_rG −13.4 kJ/mol K 2.23 × 10² pK −2.35: KFIonized aqueous solution + HIO₃Un-ionized aqueous solution
⟶
KIO₃Ionized aqueous solution + HF↑Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	2.6	−13.4	54.0	–
per 1 mol of Potassium fluoride	2.6	−13.4	54.0	–
per 1 mol of Iodic acid	2.6	−13.4	54.0	–
per 1 mol of Potassium iodate	2.6	−13.4	54.0	–
per 1 mol of Hydrogen fluoride	2.6	−13.4	54.0	–

Changes in aqueous solution (3)

Reaction of potassium fluoride and iodic acid ◆ Δ_rG −13.4 kJ/mol K 2.23 × 10² pK −2.35: KFIonized aqueous solution + HIO₃Un-ionized aqueous solution
⟶
KIO₃Ionized aqueous solution + HF↑Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	2.6	−13.4	54.0	–
per 1 mol of Potassium fluoride	2.6	−13.4	54.0	–
per 1 mol of Iodic acid	2.6	−13.4	54.0	–
per 1 mol of Potassium iodate	2.6	−13.4	54.0	–
per 1 mol of Hydrogen fluoride	2.6	−13.4	54.0	–

Changes in aqueous solution (4)

Reaction of potassium fluoride and iodic acid ◆ Δ_rG 4.7 kJ/mol K 0.15 × 10⁰ pK 0.82: KFIonized aqueous solution + HIO₃Un-ionized aqueous solution
⟶
KIO₃Ionized aqueous solution + HF↑Ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−9.9	4.7	−48.5	–
per 1 mol of Potassium fluoride	−9.9	4.7	−48.5	–
per 1 mol of Iodic acid	−9.9	4.7	−48.5	–
per 1 mol of Potassium iodate	−9.9	4.7	−48.5	–
per 1 mol of Hydrogen fluoride	−9.9	4.7	−48.5	–

Thermodynamic data of reactants

Chemical formula	Standard enthalpy of formation Δ_fH° kJ · mol⁻¹	Standard Gibbs energy of formation Δ_fG° kJ · mol⁻¹	Standard molar entropy S° J · K⁻¹ · mol⁻¹	Standard molar heat capacity at constant pressure C_p° J · K⁻¹ · mol⁻¹
KF (cr)	-567.27^[1]	-537.75^[1]	66.57^[1]	49.04^[1]
KF (g)	-325.43^[1]	-343.62^[1]	226.41^[1]	35.23^[1]
KF (ai)	-585.01^[1]	-562.06^[1]	88.7^[1]	-84.9^[1]
KF (cr) 2 hydrate	-1163.621^[1]	-1021.49^[1]	155.2^[1]	–
HIO₃ (cr)	-230.1^[1]	–	–	–
HIO₃ (ao)	-211.3^[1]	-132.6^[1]	166.9^[1]	–

* (cr):Crystalline solid, (g):Gas, (ai):Ionized aqueous solution, (ao):Un-ionized aqueous solution

Thermodynamic data of products

Chemical formula	Standard enthalpy of formation Δ_fH° kJ · mol⁻¹	Standard Gibbs energy of formation Δ_fG° kJ · mol⁻¹	Standard molar entropy S° J · K⁻¹ · mol⁻¹	Standard molar heat capacity at constant pressure C_p° J · K⁻¹ · mol⁻¹
KIO₃ (cr)	-501.37^[1]	-418.35^[1]	151.46^[1]	106.48^[1]
KIO₃ (ai)	-473.6^[1]	-411.2^[1]	220.9^[1]	–
HF (l) x denotes undetermined zero point entropy	-299.78^[1]	–	75.40+x^[1]	–
HF (g)	-271.1^[1]	-273.2^[1]	173.779^[1]	29.133^[1]
HF (ai)	-332.63^[1]	-278.79^[1]	-13.8^[1]	-106.7^[1]
HF (ao)	-320.08^[1]	-296.82^[1]	88.7^[1]	–

* (cr):Crystalline solid, (ai):Ionized aqueous solution, (l):Liquid, (g):Gas, (ao):Un-ionized aqueous solution

References

List of references

1
Janiel J. Reed (1989)
The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI Units
https://doi.org/10.18434/M32124
National Institute of Standards and Technology (NIST)
Citation list

Δ_rG	10.3 kJ/mol
K	0.16 × 10⁻¹
pK	1.80

Δ_rG	−13.4 kJ/mol
K	2.23 × 10²
pK	−2.35

Δ_rG	−13.4 kJ/mol
K	2.23 × 10²
pK	−2.35

Δ_rG	4.7 kJ/mol
K	0.15 × 10⁰
pK	0.82

KF + HIO3 → KIO3 + HF↑

Reaction data

Chemical equation

General equation

Oxidation state of each atom