JEE Main & Advanced AIEEE Solved Paper-2004

Among \[A{{l}_{2}}{{O}_{3}},Si{{O}_{2}},{{P}_{2}}{{O}_{3}}\]and \[S{{O}_{2}},\]the correct order of acid strength is

A) \[S{{O}_{2}}<{{P}_{2}}{{O}_{3}}<Si{{O}_{2}}<A{{l}_{2}}{{O}_{3}}\]

B) \[Si{{O}_{2}}<S{{O}_{2}}<A{{l}_{2}}{{O}_{3}}<{{P}_{2}}{{O}_{3}}\]

C) \[A{{l}_{2}}{{O}_{3}}<Si{{O}_{2}}<S{{O}_{2}}<{{P}_{2}}{{O}_{3}}\]

D) \[A{{l}_{2}}{{O}_{3}}<Si{{O}_{2}}<{{P}_{2}}{{O}_{3}}<S{{O}_{2}}\]

Correct Answer: D

Solution :

While moving along a group from top to bottom acidic nature of oxides decreases and along a period left to right, acidic nature increases.

	\[Al\]	\[Si\]	\[P\]	\[S\]
\[Z\]	13	14	15	16
	\[A{{l}_{2}}{{O}_{3}}\]	\[Si{{O}_{2}}\]	\[{{P}_{2}}{{O}_{3}}\]	\[S{{O}_{2}}\]
\[\xrightarrow[Amphpteric\text{ }\,\,\,\,Acidic\,\,\,\,\,\,\,~~Max.\text{ }\,\,\,\,\,\,\,\,acidic]{{}}\]

Thus,\[A{{l}_{2}}{{O}_{3}}<Si{{O}_{2}}<{{P}_{2}}{{O}_{3}}<S{{O}_{2}}\]