Iodine exists in which form in iodised salt?

When $KI$ is reacted with $O_3$ under aqueous condition,the product formed is:

What is the product formed when $Au$ reacts with aqua regia?

Which of the following oxidation states are exhibited by iodine?

The correct order of acidic strength of oxy-acids of chlorine is

When treated with conc. $HCl$,$MnO_2$ yields a gas $(X)$ which further reacts with $Ca(OH)_2$ to generate a white solid $(Y)$. The solid $Y$ reacts with dil. $HCl$ to produce the same gas $X$. The solid $Y$ is