A $0.1\, M$ solution of $HF$ is $1\%$ ionized. What is the $K_a$

What is the $pH$ of solution of $7$ $gm$ $N{H_4}OH$ per $500$ $mL$ ? ( ${K_b}$ of $N{H_4}OH 1.8 \times {10^{ - 5}}$, Molecular moles of $N{H_4}OH$ is $35\,g\,mo{l^{ - 1}}$ )

A monoprotic acid in a $0.1\,\,M$ solution ionizes to $0.001\%$. Its ionisation constant is

$K_b$ for $NH_4OH$ is $1.8\times 10^{-5}.$ The $[\mathop O\limits^\Theta  H]$ of $0.1\,M\,NH_4OH$ is

When $CO_2$ dissolves in water, the following equilibrium is established

$C{O_2} + 2{H_2}O\, \rightleftharpoons {H_3}{O^ + } + HCO_3^ - $

for which the equilibrium constant is $3.8 \times 10^{-7}$ and $pH = 6.0$. The ratio of  $[HCO_3^- ]$ to $[CO_2]$ would be :-

$K _{ a_1,}, K _{ a_2 }$ and $K _{ a_3}$ are the respective ionization constants for the following reactions $(a), (b),$ and $(c)$.

$(a)$ $H _{2} C _{2} O _{4} \rightleftharpoons H ^{+}+ HC _{2} O _{4}^{-}$

$(b)$ $HC _{2} O _{4}^{-} \rightleftharpoons H ^{+}+ HC _{2} O _{4}^{2-}$

$(c)$ $H _{2} C _{2} O _{4} \rightleftharpoons 2 H ^{+}+ C _{2} O _{4}^{2-}$

The relationship between $K_{a_{1}}, K_{ a _{2}}$ and $K_{ a _{3}}$ is given as