Question

The golden yellow colour associated with NaCl to Bunsen flame be explained on the basis of
(A) low ionization energy of sodium
(B) sublimation of metallic sodium to give yellow vapour
(C) emission of excess energy absorbed as a radiation in the visible region
(D) photosensitivity of sodium

Answer 1

Hint :The chemical formula for sodium chloride is NaCl, which represents a 1:1 ratio of sodium and chloride ions. 100 g of NaCl comprises 39.34 g Na and 60.66 g Cl, with molar weights of 22.99 and 35.45 g/mol, respectively. The salt that is mainly responsible for the saltiness of seawater and the extracellular fluid of many multicellular organisms is sodium chloride.

Complete Step By Step Answer:
Because sodium chloride crystals suffer from a metal excess defect when heated with sodium vapours, sodium chloride takes on a yellow colour when heated. It looks yellow due to an electrical transition in the excited state of the sodium atom. The Bunsen flame takes on a yellow hue when sodium chloride is added. This can be explained as a result of extra energy being absorbed and emitted as visible radiation. When an alkali or alkaline earth metal (or its salt) is heated in a flame, the metal's valence electrons absorb energy and are stimulated to a higher energy level. The absorbed energy is released as visible light when excited electrons return to their ground state. The yellow colour of NaCI comes from a metal excess defect in which unpaired electrons occupy anionic sites called F-centres. The activation of these electrons requires energy from the visible area, which causes the crystal to look yellow. The Bunsen flame takes on a yellow hue thanks to sodium chloride. This can be explained as a result of extra energy being absorbed and emitted as visible radiation.
Hence option A is correct.

Note :
Neutralization of the strong base sodium hydroxide and the strong acid hydrochloric acid produces sodium chloride solutions, reversing the energy-intensive electrolysis process that makes sodium hydroxide and hydrochloric acid more expensive than sodium chloride—and necessitates the evaporation of water from the solution, which is impractical. Similarly, it develops through a variety of solute reactions that leave sodium chloride as the residual solute in solution following a reaction between a metallic chloride (most are soluble) and an insoluble carbonate such as sodium carbonate (one of the few water-soluble carbonates).