What is the percentage dissociation of $0.1 \ M$ acetic acid (in $\%$)? $(K_a = 10^{-5})$

The $pK_a$ of acetylsalicylic acid (aspirin) is $3.5$. The $pH$ of gastric juice in the human stomach is about $2-3$ and the $pH$ in the small intestine is about $8$. Aspirin will be

The ionization constant of benzoic acid is $6.5 \times 10^{-5}$ at $298 \ K$ temperature. Calculate $pH$ of its $0.15 \ M$ solution. (in $.5$)

The hydrogen ion concentration of a $0.006 \ M$ benzoic acid solution is $(K_a = 6 \times 10^{-5})$

Calculate the $pH$ of a $0.02 \ M$ ammonia solution that is $5\%$ ionized.

$K_b$ for $NH_4OH$ is $1.8 \times 10^{-5}$. The $[OH^{-}]$ of $0.1 \ M \ NH_4OH$ is