A soft metal (A) gives violet flame test. When burnt ill excess \[{{O}_{2}}\], (A) gives chrome yellow powder (B) which on reaction with water gives alkaline solution (C) and \[{{O}_{2}}\]. Identify A and B.
A. \[Na,N{{a}_{2}}{{O}_{2}}\]
B. \[\,K,{{K}_{2}}{{O}_{2}}Z\]
C. \[\,K,K{{O}_{2}}\]
D. \[Li,Li{{O}_{2}}\]

Question

A soft metal (A) gives violet flame test. When burnt ill excess \[{{O}_{2}}\], (A) gives chrome yellow powder (B) which on reaction with water gives alkaline solution (C) and \[{{O}_{2}}\]. Identify A and B.
A. \[Na,N{{a}_{2}}{{O}_{2}}\]
B. \[\,K,{{K}_{2}}{{O}_{2}}Z\]
C. \[\,K,K{{O}_{2}}\]
D. \[Li,Li{{O}_{2}}\]

Vedantu Content Team · Accepted Answer

Hint: Potassium gives us the violet fire test. The cream of tartar yielded a purple-hued fire. Purple is related with the nearness of Potassium (). That is on the grounds that cream of tartar is a potassium salt. These component explicit hues are listed in an outflow range.

Complete step-by-step answer:
On warming a soluble base earth metal or its salt, the electrons are energized effectively to higher vitality levels due to retention of vitality.
At the point when these electrons come back to their ground states, they emanate additional vitality in type of radiations which fall in the noticeable area consequently giving a trademark shading to the fire. The violet fire appeared by potassium in Bunsen fire is because of bouncing of the electron from 5p to 4s.
The fire test is utilized to outwardly decide the personality of an obscure metal of an ionic salt dependent on the trademark shading the salt turns the fire of a Bunsen burner.
The substances in the opposition are: Sodium acetic acid derivation, sodium chloride, sodium hydrogen carbonate, sodium carbonate, lithium chloride, potassium chloride, calcium nitrate, calcium sulfate, calcium carbonate, boric corrosive, and ammonium chloride. Cornstarch, glucose, sucrose, magnesium sulfate will give a negative fire test. The right answer is C.

Note: The hues appeared by the compound in flame test are:
Red: Carmine by Lithium mixes. Veiled by sodium. Yellow-Red by the Calcium mixes.
Yellow: Sodium mixes, even in follow sums
Green: Blue-Green by the Boric corrosive. Black out Green by the alkali containing mixes.
Violet by the Potassium mixes - Masked by sodium or lithium.
Purple-Red by the Potassium within the sight of sodium when seen through cobalt blue glass.

The right answer is C. 
Note: The hues appeared by the compound in flame test are: Red: Carmine by Lithium mixes. Veiled by sodium. Yellow-Red by the Calcium mixes. Yellow: Sodium mixes, even in follow sums Green: Blue-Green by the Boric corrosive. Black out Green by the alkali containing mixes. Violet by the Potassium mixes - Masked by sodium or lithium. Purple-Red by the Potassium within the sight of sodium when seen through cobalt blue glass.