Question

Alkyl halide when heated with alcoholic solution of potassium sulphide forms:
A. Thioalcohol
B. Thioether
C. Thioacid
D. Alkane

Answer 1

Hint: In alkyl halide, the alkyl chain is going to carry a positive charge on it due to the high electronegative value of the halogens. In alkyl halide the halogen atoms are going to carry a partial negative charge.

Complete answer:
- In the reaction it is asked to find the product when alkyl halide is going to react with alcoholic potassium sulfide.
- We have to take an example for alkyl halide to write a chemical reaction between the alkyl halide and alcoholic potassium sulfide.
-The best example for alkyl halide methyl chloride or chloro methane.
- The chemical reaction between methyl chloride and alcoholic potassium sulfide is as follows.
\[\begin{align}
  & C{{H}_{3}}Cl+{{K}_{2}}S\to C{{H}_{3}}-S-K \\
 & C{{H}_{3}}-S-K+C{{H}_{3}}Cl\to C{{H}_{3}}-S-C{{H}_{3}} \\
\end{align}\]
- In the above chemical reaction, we can see that two moles of alkyl halide are going to react with one mole of potassium sulfide.
- After the reaction of one mole of methyl chloride with potassium sulfide the formed product contains a sulfur and the potassium in the formed product.
- The potassium is going to carry a partial positive charge and the sulphur is going to carry a partial negative charge in the product which is formed in the first step.
- Due to the partial negative charge on the sulphur, it is going to react with another one mole of the methyl chloride and a dimethyl thioether as the product.

So, the correct option is A.

Note:
Due to the partial positive and partial negative charges in alkyl halide and potassium sulfide, both the molecules are undergoing the substitution reactions and result in the formation of the thioethers as the product.