Question

Which of these is the weakest acid? How can you tell?

HClO2

HClO3

HBrO2

HBrO3

Answer 1

Ans - HBrO2

In this case, the chlorous acid is stronger than HBrO3 is that ClO3 is more stable in solution and more likely to be formed , thus more likely to dissociate. If the element is the same in the oxoacid, the more oxygens present, the stronger the acid
Cl is more acidic than Br is that as chlorine binds with all the oxygens, the electronegativity increases and pulls the electron density away from the OH bond, meaning that the H+ carries a stronger partial positive charge and is more likely to be released, that is, it's not being held on as tightly.