Question

The butter of tin is represented by:
A)$SnC{{l}_{2}}.5{{H}_{2}}O$
B) $SnC{{l}_{2}}$
C)$SnC{{l}_{4}}$
D) $SnC{{l}_{4}}.5{{H}_{2}}O$

Answer 1

Hint The answer is dependent on the fact that the name butter is given to the metal, because it forms mordant for dyes. This compound belongs to the post transition metal chlorides and was used in World War I and was substituted by a mixture of silicon and titanium tetrachlorides in the end of war.

Complete answer:
We have dealt with the common and special names given for several compounds in the inorganic part of the chemistry and now let us look into what is butter of tin and what are the uses so that we can approach the required answer.
- Butter of tin is a quite famous chemical which was used in World War I because it forms an irritating dense smoke when it comes in contact with air which is not deadly.
- In options A) and B), the tin chloride pentahydrate and tin chloride are not susceptible to the oxidation in air and thus are ruled out.
- Since tin has the vacant d – orbitals and also vacant f - orbitals and it can increase the covalency and the stannic chloride can form the hydrates with 2, 3, 5,6,8 molecules of water of crystallization and among this the pentahydrate of stannic chloride is well known as butter of tin.
- At room temperature, it is a colourless liquid and gives the dense fumes when it is contacted with air giving the stinging odour and stannic chloride is hygroscopic in nature.
- This compound is used as a mordant for dyes.

Thus, the correct answer is option D) $SnC{{l}_{4}}.5{{H}_{2}}O$

Note: Note that stannic chloride is also called as tin tetrachloride pentahydrate or also called as oxymuriate of tin or tin IV chloride which is mainly used as precursor to the organotin compounds that are used as catalysts and polymer stabilizers.