Calculate the $pH$ of a $2 \, L$ solution containing $0.1 \, M \, CH_3COOH$ and $0.1 \, M \, (CH_3COO)_2Ba$. Given $K_a (CH_3COOH) = 1.8 \times 10^{-5}$.

$pH$ of a mixture of $1 \ M$ benzoic acid $(pK_a = 4.20)$ and $1 \ M$ $C_6H_5COONa$ is $4.5$. What is the volume of benzoic acid required to prepare a $300 \ mL$ buffer solution (in $mL$)? $[\log 2 = 0.3]$

If $50 \, mL$ of $2 \, N$ acetic acid is mixed with $10 \, mL$ of $1 \, N$ sodium acetate solution,what will be the approximate $pH$ of the resulting solution? (Given: $K_a = 10^{-5}$)

Which of the following is a buffer solution of strong acidic nature?

Which buffer is present in human blood :-

In which of the following combinations is buffer action expected?
$(a)$ $NH_4OH + NH_4Cl$
$(b)$ $HCl + NaCl$
$(c)$ $NH_4OH + HCl$ in $2:1$ mole ratio
Select the correct answer using the code given below.