Question

A purple coloured non-metal forms a brown solution in alcohol which is applied as antiseptic. Which non-meal is this?
(A) Sulphur
(B) Chlorine
(C) Oxygen
(D) Iodine

Answer 1

Hint: The non-metal is part of the 17th group of the periodic table. The non-metal is used for the detection of starch in a complex organic compound. The non-metal is crucial for the production of the hormone thyroxine.

Complete step by step solution:
Iodine is a chemical element with atomic number 53 and symbol "I". It lies in the 17th group of the periodic table and is the heaviest of stable halogen elements.
It exists as a lustrous, purple-black non-metallic solid at standard temperature and pressure (STP). At${{114}^{0}}C$, solid iodine melts to form a deep violet liquid and boils to a deep violet gas at${{184}^{0}}C$. The element was discovered in 1811 and named two years later by Joseph Louis Gay-Lussac.
Iodine occurs in various oxidation states including periodate ions. However, the most common oxidation states are ${{\text{I}}^{-}}$and $\text{I}{{\text{O}}_{3}}^{-}$.It is the least abundant in the group of halogens and is the 61st most abundant element found. Iodine is essential for the synthesis of thyroxin hormone secreted by the thyroid gland. Iodine deficiency affects about two billion people every year and is a major reason for intellectual disabilities.
Iodine along with alcohol is called tincture of iodine. It is widely used as an antiseptic. The colour of the solution is brown and had a pungent odour.

Therefore, the metal is iodine and the correct answer is option (D).

Note: Starch iodide paper consists of potassium iodide and starch. It is used for the detection of nitrite and free chlorine atoms. Free chlorine and nitrite ion readily accept an electron to gain their stable configuration. As they get reduced, they end up oxidizing the iodide ion present in the form of potassium iodide. We can say that starch iodide is used to detect oxidizing agents.