pH Buffer Solutions

Rank the following in terms of acidity: HClO, IOH, and HBrO. Explain the trend.

Rank the following in terms of acidity: HClO, HClO$_2$, HClO$_3$, HClO$_4$. Explain the trend.

A buffer solution consisting of 0.60 M HF and 1.0 M KF (Ka of HF = 7.2 x 10$^-4$) is titrated by 0.2 mol HCl. After the HCl is added, there is 1 L of solution. Find the pH of the solution.

Find the pH of the buffer solution consisting of 0.100 M HONH$_2$ and 0.100 M HONH$_3^+$ (K$_b$ of HONH$_2$ = 1.1 x 10$^{-8}$), after .02 moles HCl is added to the buffer solution? (assume the final volume of the solution is 1 L)