What is the $[OH^-]$ in the final solution prepared by mixing $20.0 \ mL$ of $0.050 \ M \ HCl$ with $30.0 \ mL$ of $0.10 \ M \ Ba(OH)_2$?

The percentage of ionization of $1 \ L$ of $x \ M$ acetic acid is $4.242$ and is called solution "$A$". The percentage of ionization of $1 \ L$ of $y \ M$ acetic acid is $3$ and is called solution "$B$". Solution "$A$" is mixed with solution "$B$". What is the concentration of acetic acid in the resultant solution (in $M$)? $\left(K_{a} \text{ of acetic acid } = 1.8 \times 10^{-5}\right)$

$K_a$ for $CH_3COOH$ is $1.9 \times 10^{-5}$. Calculate the $pH$ at the equivalence point in the titration of $0.1 \ M$ $CH_3COOH$ with $0.1 \ M$ $NaOH$.

The ionization constant of propanoic acid is $1.32 \times 10^{-5}$. Calculate the degree of ionization of the acid in its $0.05 \, M$ solution and also its $pH$. What will be its degree of ionization if the solution is $0.01 \, M$ in $HCl$ also?

$A$ sample of $MgCO_3$ is dissolved in dil. $HCl$ and the solution is neutralized with ammonia and buffered with $NH_4Cl / NH_4OH$. Disodium hydrogen phosphate reagent is added to the resulting solution. $A$ white precipitate is formed. What is the formula of the precipitate?

For a $0.1 \, M$ aqueous solution of a weak acid undergoing $2\%$ ionization,the concentration of $[H^{+}]$ and $[OH]^{-}$ will be respectively: (Ionic product of water $= 1 \times 10^{-14}$)