The key difference between sodium cyanide and potassium cyanide is that sodium cyanide is produced via treating hydrogen cyanide with sodium hydroxide, whereas potassium cyanide is produced via treating hydrogen cyanide with potassium hydroxide.
Sodium cyanide and potassium cyanide are mainly used in gold mining though they are highly toxic compounds. These are useful in gold mining due to their high reactivity towards metals. Since only the cation is different in the chemical formulas of these two compounds and the cations are from the same group in the periodic table, they have nearly similar physical and chemical properties.
CONTENTS
1. Overview and Key Difference
2. What is Sodium Cyanide
3. What is Potassium Cyanide
4. Similarities Between Sodium Cyanide and Potassium Cyanide
5. Side by Side Comparison – Sodium Cyanide vs Potassium Cyanide in Tabular Form
6. Summary
What is Sodium Cyanide?
Sodium cyanide is an inorganic compound having the chemical formula NaCN. It appears as a white solid and this solid is highly water-soluble. It has a faint, almond-like odour. The cyanide anion has a high affinity for metals; therefore, this compound is highly reactive towards metals. Moreover, it is highly toxic due to the same reason of high reactivity. This is a salt compound formed from the reaction between hydrogen cyanide acid and sodium hydroxide base. However, sodium cyanide is a moderately strong base. If we add some acid to this compound, it emits hydrogen cyanide gas. The molar mass of sodium cyanide is 49 g/mol. The melting point is 563.7 °C while the boiling point is 1,496 °C.
The structure of this compound resembles the structure of sodium chloride. Each anion and cation are six-coordinated atoms in this structure. Each sodium cation forms pi bonds with two cyanide groups. There are many applications of sodium cyanide: to extract gold in gold mining, as a chemical feedstock for the production of different compounds such as cyanuric chloride, etc.
What is Potassium Cyanide?
Potassium cyanide is an inorganic compound having the chemical formula KCN. It is a colourless crystalline solid which appears as sugar. It is highly water-soluble and is deliquescent as well. Furthermore, this compound is highly toxic. It has a faint almond-like odour. The molar mass of potassium cyanide is 65.12 g/mol. Its melting point is 634.5 °C while its boiling point is 1,625 °C. Also, this compound is a salt which forms from the reaction between hydrogen cyanide acid and potassium hydroxide base. In the production process, we need to treat hydrogen cyanide with aqueous potassium hydroxide, followed by vacuum drying.
Potassium cyanide has many applications including uses in organic synthesis for the preparation of nitriles, use in gold mining for the extraction of gold, electroplating, as a photographic fixer, etc.
What are the Similarities Between Sodium Cyanide and Potassium
Cyanide?
- Both sodium cyanide and potassium cyanide are important salt compounds which are highly toxic but very useful in gold mining.
- These compounds have a faint, almond-like odour.
What is the Difference Between Sodium Cyanide and Potassium Cyanide?
The key difference between sodium cyanide and potassium cyanide is that sodium cyanide is produced via treating hydrogen cyanide with sodium hydroxide, whereas potassium cyanide is produced via treating hydrogen cyanide with potassium hydroxide. Furthermore, sodium cyanide appears as a white solid while potassium cyanide appears as a colourless crystalline solid which resembles the appearance of sugar.
Below infographic tabulates more comparisons related to the difference between sodium cyanide and potassium cyanide.
Summary – Sodium Cyanide vs Potassium Cyanide
Both sodium cyanide and potassium cyanide are important salt compounds which are highly toxic but very useful in gold mining. However, the key difference between sodium cyanide and potassium cyanide is that sodium cyanide is produced via treating hydrogen cyanide with sodium hydroxide, whereas potassium cyanide is produced via treating hydrogen cyanide with potassium hydroxide. Here, sodium cyanide has a sodium cation bound to cyanide anion, while potassium cyanide has a potassium cation in the place of the sodium cation.
Reference:
1. “Sodium Cyanide.” Wikipedia, Wikimedia Foundation, 4 Oct. 2019, Available here.
2. “Potassium Cyanide.” Wikipedia, Wikimedia Foundation, 18 Nov. 2019, Available here.
Image Courtesy:
1. “Sodium cyanide” By Epop – Own work, Public Domain) via Commons Wikimedia
2. “Potassium-cyanide-phase-I-unit-cell-3D-SF” By Ben Mills – Own work (Public Domain) via Commons Wikimedia