Given below are two statements, one is labelled as Assertion $A$ and the other is labeled 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 from the options given below

Question

Statement-I: An element ‘X’ of P-block forms a hydride H–X, which has the longest bond length, then element ‘X’ will have the shortest covalent radius.
Statement-II: An element ‘E’ of Group 15 forms hydride EH$_3$, that has least B.P. The maximum covalency of E is 4.

Answer 1

The question involves two statements, one labeled as Assertion $A$ and the other as Reason $R$. We are provided with four options to determine the relationship between these statements.

Let's first evaluate the Assertion $A$: The statement mentions "The alkali metals and their salts impart characteristic colour to reducing flame." This statement is incorrect because alkali metals and their salts impart characteristic colors to flames in general, not specifically to a 'reducing flame'. The term "reducing flame" itself is more associated with combustion reactions rather than the flame test, which typically employs a non-luminous or oxidizing flame for better visibility of the characteristic colors.
Now, let's consider the Reason $R$: The statement "Alkali metals can be detected using flame tests" is indeed correct. Flame tests are a reliable method to detect alkali metals due to their ability to exhibit distinct colors when introduced to a flame. For instance, lithium gives a crimson red color, sodium gives a bright yellow, and potassium gives a lilac or light purple color.
Next, we need to compare the correctness and relationship between $A$ and $R$: Since $A$ is incorrect but $R$ is correct, the most appropriate answer aligns with the option that states, "$A$ is not correct but $R$ is correct".

Hence, the correct option is: $A$ is not correct but $R$ is correct.

Answer 2

The question involves two statements, one labeled as Assertion $A$ and the other as Reason $R$. We are provided with four options to determine the relationship between these statements.

Let's first evaluate the Assertion $A$: The statement mentions "The alkali metals and their salts impart characteristic colour to reducing flame." This statement is incorrect because alkali metals and their salts impart characteristic colors to flames in general, not specifically to a 'reducing flame'. The term "reducing flame" itself is more associated with combustion reactions rather than the flame test, which typically employs a non-luminous or oxidizing flame for better visibility of the characteristic colors.
Now, let's consider the Reason $R$: The statement "Alkali metals can be detected using flame tests" is indeed correct. Flame tests are a reliable method to detect alkali metals due to their ability to exhibit distinct colors when introduced to a flame. For instance, lithium gives a crimson red color, sodium gives a bright yellow, and potassium gives a lilac or light purple color.
Next, we need to compare the correctness and relationship between $A$ and $R$: Since $A$ is incorrect but $R$ is correct, the most appropriate answer aligns with the option that states, "$A$ is not correct but $R$ is correct".

Hence, the correct option is: $A$ is not correct but $R$ is correct.

The Correct Option is A

Solution and Explanation

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