Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion A :- The alkali metals and their salts impart characteristic colour to reducing flame.
Reason R :- Alkali metals can be detected using flame tests.
In the light of the above statements, choose the most appropriate answer form the options given below
Assertion A :- The alkali metals and their salts impart characteristic colour to reducing flame.
Reason R :- Alkali metals can be detected using flame tests.
In the light of the above statements, choose the most appropriate answer form the options given below
- (A)Both A and R are correct but R is NOT the correct explanation of A .
- (B)A is correct but R is not correct.
- (C)A is not correct but R is correct✓ Correct
- (D)Both A and R are correct and R is the correct explanation of A .
Answer: (C)
Solution
The characteristic colour of an alkali metal appears when its salt is heated in the non-luminous oxidising flame, not in the reducing flame, so the assertion as worded is wrong. The valence electron absorbs the flame's energy, rises to a higher level and emits light of a definite colour as it falls back, which is the basis of the flame test used to detect alkali metals, so the reason is correct. The assertion is therefore not correct while the reason is correct.
JEE Main · 2023 · 25 Jan 2023 · Shift 2 · Single correct option