Potassium iodide
Potassium iodide is an inorganic compound with formula KI.
- 1Names
- 2Formulae and structures
- 3Properties
- 4Constituents
- 5Thermodynamic properties
- 6Solubility
- 7Hazards
- 8Preparations
- 9Chemical reactions
- 10References
- 11Related substances
- 12Related categories
Names
List of substance names
- Typical name
- Potassium iodide
- Compositional nomenclature
- Potassium iodide
Formulae and structures
List of formulae
- Typical formula
- KI
- Compositional formula
- KI
- Structural formula
- Lewis structure
- Colored Lewis structure
Properties
List of substance properties
Constituents
Constituent ions
Ion | Name | Charge number | Number |
---|---|---|---|
K+ | Potassium ion | 1 | 1 |
I− | Iodide ion | -1 | 1 |
Constituent atoms
Atom | Name | Oxidation state | Number |
---|---|---|---|
K | Potassium | +1 | 1 |
I | Iodine | −1 | 1 |
Ratio of atoms
Atom | Atomic weight | Number | Atomic ratio | Weight ratio |
---|---|---|---|---|
K | 39.0983 | 1 | 50.00% | 23.55% |
I | 126.90 | 1 | 50.00% | 76.45% |
Thermodynamic properties
Phase transition properties
Standard thermodynamic properties
State | Standard enthalpy of formation ΔfH° kJ · mol−1 | Standard Gibbs energy of formation ΔfG° kJ · mol−1 | Standard molar entropy S° J · K−1 · mol−1 | Standard molar heat capacity at constant pressure Cp° J · K−1 · mol−1 |
---|---|---|---|---|
Crystalline solid | −327.900[3] | −324.892[3] | 106.32[3] | 52.93[3] |
Gas | −125.5[3] | −166.1[3] | 258.3[3] | 37.11[3] |
Ionized aqueous solution | −307.57[3] | −334.85[3] | 213.8[3] | −120.5[3] |
Solubility
Qualitative solubility
Solubility in water (g/100 g)[4]
0°C | 10°C | 20°C | 30°C | 40°C | 60°C | 80°C | 90°C | 100°C |
---|---|---|---|---|---|---|---|---|
128 | 136 | 144 | 153 | 162 | 176 | 192 | 198 | 206 |
Solubility in water (g/100 g)[4]
-10°C | -5°C | -1°C | 0°C | 10°C | 20°C | 25°C | 30°C | 40°C | 50°C | 60°C | 70°C | 80°C | 90°C | 100°C | 110°C | 120°C |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
115.1 | 119.8 | 122.2 | 127.5 | 136 | 144 | 148 | 152 | 160 | 168 | 176 | 184 | 192 | 200 | 208 | 215 | 223 |
Solubility in hydroxylamine (g/100 g)[4]
17.5°C |
---|
110 |
Solubility in glycerol (g/100 g)[4]
15.5°C |
---|
40 |
Solubility in acetic acid (g/100 g, 95%)[4]
18.5°C |
---|
38.2 |
Solubility in methanol (g/100 g)[4]
11.4°C | 12.2°C | 13.5°C | 25°C |
---|---|---|---|
13.5 | 14.6 | 16 | 18.04 |
Solubility in methanol (g/100 g)[4]
15°C | 30°C | 50°C | 80°C | 100°C | 120°C | 140°C | 160°C | 180°C | 200°C | 220°C | 240°C | 245°C | 247°C | 250°C | 252.5°C |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
14.5 | 16.2 | 18.9 | 22.5 | 25 | 27.2 | 29.2 | 30.6 | 30.7 | 29.1 | 27.5 | 24.8 | 22.6 | 21 | 13.8 | 7.6 |
Solubility in acetone (g/100 g)[4]
-2.5°C | 22°C | 25°C | 56°C |
---|---|---|---|
3.08 | 2.38 | 2.93 | 1.21 |
Solubility in ethanol (g/100 g)[4]
13.6°C | 25°C |
---|---|
1.63 | 2.16 |
Solubility in 1-propanol (g/100 g)[4]
12.2°C | 25°C |
---|---|
0.731 | 0.43 |
Solubility in pyridine (g/100 g)[4]
10°C | 119°C |
---|---|
0.26 | 0.11 |
Solubility in 1-pentanol (g/100 g)[4]
25°C |
---|
0.098 |
Solubility in hydrazine (g/100 mL)[4]
20°C |
---|
175 |
Solubility in water (g/100 mL)[1]
20°C |
---|
144 |
Solubility in glycerol (g/100 mL)[1]
20°C |
---|
50 |
Solubility in ethanol (g/100 mL)[1]
20°C |
---|
4.5 |
Solubility curve (g/100 g)
Solubility curve (g/100 mL)
Hazards
GHS label[5]
- Hazard pictograms
GHS08: Health hazard
- Signal word
- Danger
- Hazard statements
- H320: Causes eye irritation
- H360: May damage fertility or the unborn child
- H362: May cause harm to breast fed children
- H370: Causes damage to organs
- H370: Causes damage to thyroid
- H372: Causes damage to organs through prolonged or repeated exposure
- H372: Causes damage to skin through prolonged or repeated exposure
- H372: Causes damage to thyroid through prolonged or repeated exposure
- H372: Causes systemic toxicity through prolonged or repeated exposure
Physical hazards[5]
Health hazards[5]
Environmental hazards[5]
Preparations
Reaction of metal and nonmetal
The reaction of and yields potassium iodide.
Reaction of acid and base
The reaction of hydrogen iodide and potassium hydroxide yields potassium iodide and water.
Reaction of basic oxide and acid
The reaction of potassium oxide and hydrogen iodide yields potassium iodide and water.
Reaction of salt of weak acid and strong acid
The reaction of salt of weak acid and strong acid can yield potassium iodide.
Reaction of salt of weak base and strong base
The reaction of salt of weak base and strong base can yield potassium iodide.
Reaction of active metal and acid
The reaction of and hydrogen iodide yields potassium iodide and .
Reaction of nonmetal and hydroxide base
The reaction of and potassium hydroxide yields potassium iodate, potassium iodide, and water.
Decomposition
Decomposition of thermally decomposable substance can yield potassium iodide.
Chemical reactions
Electrolytic dissociation
Electrolytic dissociation of potassium iodide yields potassium ion and iodide ion.
Reaction with nonvolatile acid
The reaction of potassium iodide and nonvolatile acid yields salt of non volatile acid and hydrogen iodide.
Reaction with oxidizing species
The reaction of potassium iodide and oxidizing species yields a variety of products.
Reaction with oxidizing species under acidic condition
The reaction of potassium iodide, oxidizing species, and hydrogen ion yields a variety of products.
Reaction with oxidizing species under neutral condition
The reaction of potassium iodide, oxidizing species, and water yields a variety of products.
Reaction with reducible species
The reaction of potassium iodide and reducible species yields a variety of products.
Reaction with reducing species
The reaction of and potassium iodide yields sodium iodide and .
Precipitation reaction
When a certain chemical species is present in aqueous solution, it reacts with potassium iodide to form a precipitate.
Electrolysis of aqueous solution
Electrolysis of aqueous potassium iodide yields a variety of products.
Molten salt electrolysis
Molten salt electrolysis of potassium iodide yields and .
References
List of references
- 1James G. Speight (2017)Lange's Handbook of Chemistry, 17th editionMcGraw Hill Education
- ^ Density, 3.12 g/cm3 - p.58
- ^ Melting point, 681 °C - p.58
- ^ Boiling point, 1345 °C - p.58
- ^ Enthalpy of fusion, 24.0 kJ · mol−1 - p.308
- ^ Enthalpy of vaporization, 190.9 kJ · mol−1 - p.308
- ^ Enthalpy of vaporization at 25°C, 202.4 kJ · mol−1 - p.308
- ^ Solubility in Water (g/100 mL), See the table - p.58
- ^ Solubility in Glycerol (g/100 mL), See the table - p.58
- ^ Solubility in Ethanol (g/100 mL), See the table - p.58
- 2John R. Rumble Jr, David R. Lide, Thomas J. Bruno (2019)CRC Handbook of Chemistry and Physics 100th EditionCRC Press
- ^ Density, 3.12 g/cm3 - p.4-48
- ^ Melting point, 681 °C - p.4-48
- ^ Boiling point, 1323 °C - p.4-48
- ^ Enthalpy of fusion, 24.0 kJ · mol−1 - p.6-159
- 3Janiel J. Reed (1989)The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI UnitsNational Institute of Standards and Technology (NIST)
- ^ ΔfH°, -327.900 kJ · mol−1
- ^ ΔfG°, -324.892 kJ · mol−1
- ^ S°, 106.32 J · K−1 · mol−1
- ^ Cp°, 52.93 J · K−1 · mol−1
- ^ ΔfH°, -125.5 kJ · mol−1
- ^ ΔfG°, -166.1 kJ · mol−1
- ^ S°, 258.3 J · K−1 · mol−1
- ^ Cp°, 37.11 J · K−1 · mol−1
- ^ ΔfH°, -307.57 kJ · mol−1
- ^ ΔfG°, -334.85 kJ · mol−1
- ^ S°, 213.8 J · K−1 · mol−1
- ^ Cp°, -120.5 J · K−1 · mol−1
- 4Atherton Seidell (1919)Solubilities of Inorganic and Organic Compounds: A Compilation of Quantitative Solubility Data From the Periodical LiteratureD. Van Nostrand Company
- ^ Solubility in Water (g/100 g), See the table
- ^ Solubility in Water (g/100 g), See the table - p.537
- ^ Solubility in Hydroxylamine (g/100 g), See the table - p.540
- ^ Solubility in Glycerol (g/100 g), See the table - p.540
- ^ Solubility in Acetic acid (g/100 g), See the table - p.540
- ^ Solubility in Methanol (g/100 g), See the table - p.538
- ^ Solubility in Methanol (g/100 g), See the table
- ^ Solubility in Acetone (g/100 g), See the table - p.540
- ^ Solubility in Ethanol (g/100 g), See the table - p.538
- ^ Solubility in 1-Propanol (g/100 g), See the table - p.538
- ^ Solubility in Pyridine (g/100 g), See the table - p.540
- ^ Solubility in 1-Pentanol (g/100 g), See the table - p.538
- ^ Solubility in Hydrazine (g/100 mL), See the table - p.540
- 5Chemical Management CenterGHS Classification ResultsNational Institute of Technology and Evaluation