Calculate the pH of buffer solution containing 0.1M $\text{CH}_3\text{COOH}$ and 0.1 M $\text{CH}_3\text{COONa}$ $[K_a = 1.8 \times 10^{-5}]$

What is the pH of 1 molar HCl solution? (assume complete dissociation)

What is the oxidation state of Xe in $\text{XeOF}_4$?

What is the oxidation number of Cl in $\text{HOClO}_2$?