Question

In which of the following, oxides of three elements \(X\), \(Y\) and \(Z\) are correctly arranged in the increasing order of acidic nature. The electronic configurations of \(X\), \(Y\) and \(Z\) are \([\text{Ne}]3s^23p^1\), \([\text{Ne}]3s^23p^5\), \([\text{Ne}]3s^2\) respectively.

• A. \(X\lt Y\lt Z\)
• B. \(Y\lt Z\lt X\)
• C. \(Z\lt X\lt Y\)
• D. \(X\lt Z\lt Y\)

Hint:

Across a period, metallic character decreases and non-metallic character increases. Therefore, acidic nature of oxides generally increases from left to right.

Answer 1

The Correct Option is C

Step 1: Identify the elements from their electronic configurations.
X: $[Ne]3s^2 3p^1$ = Aluminium (Al, Z=13). Y: $[Ne]3s^2 3p^5$ = Chlorine (Cl, Z=17). Z: $[Ne]3s^2$ = Magnesium (Mg, Z=12).
Step 2: Determine the type of oxide each element forms.
Mg (Z) forms MgO (basic oxide). Al (X) forms $Al_2O_3$ (amphoteric oxide). Cl (Y) forms $Cl_2O_7$ (strongly acidic oxide).
Step 3: Apply the periodic trend for oxide nature.
Across a period left to right, metallic character decreases and non-metallic character increases. Oxide nature shifts from basic to amphoteric to acidic as electronegativity increases.
Step 4: Rank oxides in increasing order of acidic nature.
MgO (basic) $<$ $Al_2O_3$ (amphoteric) $<$ $Cl_2O_7$ (strongly acidic), i.e., Z $<$ X $<$ Y.
Step 5: Match with options.
The arrangement Z $<$ X $<$ Y matches option (3).
Step 6: State the final answer.
\[ \boxed{Z < X < Y} \]