Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:
Assertion (A): BeCl2 and MgCl2 produce characteristic flame.
Reason (R) : The excitation energy is high in BeCl2 and MgCl2
In the light of the above statements, choose the correct answer from the option given below
Assertion (A): BeCl2 and MgCl2 produce characteristic flame.
Reason (R) : The excitation energy is high in BeCl2 and MgCl2
In the light of the above statements, choose the correct answer from the option given below
Show Hint
Flame tests are effective for metals with low ionization energies, like alkali metals
- Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
- (A) is false but (R) is true
- Both (A) and (R) are true and (R) is the correct explanation of (A)
- (A) is true but (R) is false.
The Correct Option is D
Solution and Explanation
Analysis of Beryllium and Magnesium Flame Test
Key Observations:
- Beryllium (Be) and Magnesium (Mg) have exceptionally high ionization energies due to their small atomic size and strong nuclear attraction.
- High ionization energies prevent sufficient excitation of electrons to higher energy levels when exposed to a flame.
- As a result, neither element produces a characteristic flame color during flame tests.
Assertion (A) and Reason (R):
- Assertion (A): Beryllium and magnesium produce a flame color due to their excitation energy. This is false because no characteristic color is observed for these elements.
- Reason (R): The high ionization energy of Be and Mg prevents electron excitation to higher energy levels. This is correct.
Conclusion:
The assertion (A) is false, but the reason (R) correctly explains why Be and Mg do not exhibit a characteristic flame color.
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