Question

Given below are two statements: Statement I: Elements \(X\) and \(Y\) are the most and least electronegative elements, respectively, among \(N\), \(As\), \(Sb\) and \(P\). The nature of the oxides \(X_2O_3\) and \(Y_2O_3\) is acidic and amphoteric, respectively. Statement II: \(BCl_3\) is covalent in nature and gets hydrolysed in water. It produces \([B(OH)_4]^-\) and \([B(H_2O)_6]^{3+}\) in aqueous medium. In the light of the above statements, choose the correct answer from the options given below:

• A. Statement I is true but Statement II is false
• B. Both Statement I and Statement II are true
• C. Statement I is false but Statement II is true
• D. Both Statement I and Statement II are false

Hint:

Oxides of non-metals are acidic, while oxides of heavier \(p\)-block elements often show amphoteric character.

Answer 1

The Correct Option is A

Step 1: Analyze Statement I.
Among the elements \(N\), \(P\), \(As\) and \(Sb\): \[ \text{Electronegativity order: } N>P>As>Sb. \] Thus, \(X = N\) (most electronegative) and \(Y = Sb\) (least electronegative).
The oxide \(N_2O_3\) is acidic in nature, while \(Sb_2O_3\) is amphoteric. Hence, Statement I is true.

Step 2: Analyze Statement II.
Although \(BCl_3\) is covalent and undergoes hydrolysis in water, it does not produce both \([B(OH)_4]^-\) and \([B(H_2O)_6]^{3+}\). The ion \([B(H_2O)_6]^{3+}\) is characteristic of \(Al^{3+}\), not boron.
Thus, Statement II is false.

Final Answer: \[ \boxed{\text{Statement I is true but Statement II is false}} \]