Potassium Thiocyanate consists of the elements Potassium, Sulfur, Carbon, and Nitrogen. Potassium is soft silvery-white metal present in group-1 of the periodic table. Its atomic number is 19 and is represented with the symbol K. When it is exposed to atmospheric oxygen it forms flaky white potassium peroxide. Sulfur is an abundant non-metal present in group-16 of the periodic table. Its atomic number is 16 and is represented with the symbol S. At room temperature, It appears in bright yellow, crystalline solid form. Carbon is a nonmetal present in group-14 of the periodic table. Its atomic number is 6 and is represented with the symbol C. Nitrogen is colorless, odorless, tasteless gas and the most plentiful element in Earth’s atmosphere. It is represented with the symbol N.
What is Potassium Thiocyanate?
Potassium Thiocyanate is an inorganic, colorless, odorless, transparent prismatic crystal with the chemical formula KSCN. It has a cooling saline taste.
The other names of Potassium Thiocyanate are Potassium rhodanide, Potassium rhodanine, and Potassium sulfocyanate. This compound is formed by the fusion of sulfur with potassium cyanide, extraction with hot aqueous alcohol, evaporating, and cooling. Potassium Thiocyanate when dissolved in water produces a dark blue solution.
Structure of Potassium Thiocyanate
Potassium Thiocyanate structure
Physical Properties of Potassium Thiocyanate
- The appearance of Potassium Thiocyanate is of form colorless transparent prismatic crystals.
- It is an odorless compound.
- The molar mass of Potassium Thiocyanate is 97.181 g/mol.
- The melting point of Potassium Thiocyanate is 173 °C.
- The boiling point of Potassium Thiocyanate is 500 °C.
- Potassium Thiocyanate density is 1.89 g/cm3.
- Its heat capacity is 298.15 KJ/mol.K and its solubility in water is 177 g/100ml.
Chemical Properties of Potassium Thiocyanate
- Potassium thiocyanate reacts with iron chloride (FeCl3) to form Iron(III) Thiocyanate and Potassium chloride. The chemical reaction of this is given by-
FeCl3 + 3KSCN → Fe(SCN)3 + 3KCl
- Potassium thiocyanate reacts with Iron(III) nitrate (Fe(NO3)3) to form Iron(III) Thiocyanate, Potassium oxide, and Nitric acid.
6KSCN + 2Fe(NO3)3 + 3H2O → 2Fe(SCN)3 + 3K2O + 6HNO3
Uses of Potassium Thiocyanate
- Potassium Thiocyanate is used as bleach and disinfectant.
- It is used to prevent corrosion at steel joints.
- Potassium Thiocyanate along with Sodium Thiocyanate is used in the management of essential hypertension.
- Potassium Thiocyanate acts as a stabilizer as well as a sensitizer in the photographic field.
- It is used as a reagent in analytical chemistry.
- Used in Metallurgy for extraction of rare metals like Thorium, Zirconium, etc.
- It is a perfect intermediate in pesticide manufacturing.
Sample Questions
Question 1: Is Potassium Thiocyanate hazardous to health?
Answer:
Yes. It is hazardous to health. When this chemical comes in contact with eye it causes redness and a lot of pain. Direct skin contact causes irritation. Ingestion may cause vomiting, headache, dizziness.
Question 2: Determine the molar mass of Potassium Thiocyanate.
Answer:
Since,
Atomic weight of potassium = 39.0983
Atomic weight of Sulfur = 32.065
Atomic weight of Carbon = 12.011
Atomic weight of Nitrogen = 14.0067
Therefore,
Molecular weight of KSCN = 39.0983 + 32.065 + 12.011 + 14.0067
= 97.181
Question 3: Is Potassium Thiocyanate ionic or covalent?
Answer:
Potassium Thiocyanate is an ionic compound. When dissolved in water it dissociates into potassium cation (K+) and thiocyanate anion (CSN–).
Question 4: What happens when Potassium Thiocyanate reacts with cyclohexene oxide?
Answer:
Potassium Thiocyanate converts cyclohexene oxide to corresponding episulfide. The chemical reaction of it is given below-
KSCN + C6H10O → C6H10S + KOCN
Question 5: What are the uses of Potassium Thiocyanate?
Answer:
Potassium Thiocyanate is used as a disinfectant and prevents rust at steel joints. It is used in extraction of rare metals. It is also used as an analytical reagent in the synthesis of antibiotics.
Question 6: What happens when Potassium Thiocyanate reacts with Lead(II) Nitrate?
Answer:
Aqueous Potassium Thiocyanate (KSCN) reacts with Lead(II) Nitrate (Pb(NO3)2) to give Lead(II) thiocyanate (Pb(SCN)2), which is used to convert acyl chlorides to isothiocyanates.