The key difference between stannic and stannous chloride is that stannic chloride has the +4 oxidation state of tin, whereas stannous chloride has the +2 oxidation state of tin.
The names stannic and stannous refer to the chemical element tin having two different oxidation states. Stannic chloride is tin(IV) chloride while stannous chloride is tin(II) chloride.
CONTENTS
1. Overview and Key Difference
2. What is Stannic Chloride
3. What is Stannous Chloride
4. Side by Side Comparison – Stannic vs Stannous Chloride in Tabular Form
5. Summary
What is Stannic Chloride?
Stannic chloride is tin(IV) chloride. It is also known as tin tetrachloride, which is an inorganic compound having the chemical formula SnCl4. This compound is a colourless hygroscopic liquid which undergoes fuming upon contact with air. It has an acrid odour. This compound is important as a precursor for the production of other tin-containing compounds. It was discovered by the scientist Andreas Libavius.
Figure 01: Stannic Chloride Compound
We can prepare stannic chloride via the reaction between chlorine gas and tin metal at 115 Celsius degrees. Furthermore, this compound solidifies at about minus 33 Celsius degrees temperature. This solidification gives monoclinic crystals, and this structure is isostructural with SnBr4. There are several known hydrates of stannic chloride, such as the pentahydrate form. The hydrated structure has additional water molecules that link the stannic chloride molecules together through hydrogen bonds.
When considering the uses of stannic chloride, the main application of this compound is as a precursor to organotin compounds that are useful as catalysts and polymer stabilizers. We can use this compound in sol-gel process in order to prepare SnO2 coating, nanocrystals of SnO2, etc.
What is Stannous Chloride?
Stannous chloride is tin(II) chloride. It appears as a white crystalline solid having the chemical formula SnCl2. The major form of this compound is the dihydrate form, but the aqueous solutions of stannous chloride tend to undergo hydrolysis when the solution is hot. Moreover, SnCl2 is widely used as a reducing agent, and it is also important in electrolytic baths for tin-plating. This white solid is odourless, which is a difference from stannic chloride.
The SnCl2 molecule has a lone electron pair; therefore, this molecule has a bent geometry in its gas phase. When the solid-state of stannous chloride is considered, it forms a chain structure that is linked via chloride bridges.
Figure 02: Structures of Stannous Chloride in Different Phases
We can prepare stannous chloride via the action of dry halogen chloride gas on tin metal. We can produce the dihydrate form by a similar reaction using the HCl acid. Thereafter, the water present in the solution has to be carefully removed via evaporation to get the crystals of dihydrate stannous chloride. This dihydrate form can undergo dehydration to anhydrous form using acetic anhydride.
There are many different uses of stannous chloride including the tin plating of steel, as a mordant in textile dyeing because it gives bright colours with some dyes, as a protecting agent against enamel erosion in toothpaste, as a catalyst in the production of PLA plastic material, as a reducing agent, etc.
What is the Difference Between Stannic and Stannous Chloride?
The names stannic and stannous refer to the chemical element tin having two different oxidation states. The key difference between stannic and stannous chloride is that stannic chloride has the +4 oxidation state of tin, whereas stannous chloride has the +2 oxidation state of tin. When considering the preparation of these two compounds, stannic chloride can be made via the reaction between chlorine gas and tin metal at 115 Celsius degrees. Stannous chloride can be made via the action of dry halogen chloride gas on tin metal.
Below infographic lists more differences between stannic and stannous chloride.
Summary – Stannic vs Stannous Chloride
The names stannic and stannous refer to the chemical element tin having two different oxidation states. The key difference between stannic and stannous chloride is that stannic chloride has the +4 oxidation state of tin, whereas stannous chloride has the +2 oxidation state of tin.
Reference:
1. “Stannous Chloride.” Stannous Chloride – an Overview | ScienceDirect Topics, Available here.
Image Courtesy:
1. “Tin(IV) chloride pentahydrate” (Public Domain) via Commons Wikimedia
2. “SnCl2 structure” By Hbf878 – Own work (CC0) via Commons Wikimedia