Section-D: Comprehension Type
Binary acids contain only hydrogen and another non-metal. Their strengths increase from top to bottom within a group and from left to right across a period. Oxoacids, which contain oxygen atoms in addition to hydrogen and another element, increase' in strength as the number of oxygen atoms on the same central atom increases. Delocalisation of negative charge enhances the stability of the oxoacid anions, making them weaker bases and as a result, their conjugate acids are correspondingly stronger. Oxoacids having the same number of oxygen atoms generally increase in strength as the central atom moves from left to right.
The strongest acid of the following is :