$pH$ of a solution of $10 \ mL$ $1 \ N$ sodium acetate and $50 \ mL$ $2 \ N$ acetic acid $(K_a = 1.8 \times 10^{-5})$ is approximately

All the given solutions have the same concentration. Mixing equal volumes of which of the following will produce a buffer solution?
$A = NH_4Cl$; $B = CH_3COONa$; $C = NH_4OH$; $D = CH_3COOH$

$A$ certain buffer solution contains equal concentrations of $X^-$ and $HX$. If the $K_a$ of $HX$ is $10^{-8}$,then the $pH$ of the buffer solution will be ...... .

The constant acidity and basicity of a buffer solution is due to........

The $pK_a$ of a weak acid is $4.8$. What should be the ratio of $\frac{[\text{acid}]}{[\text{salt}]}$,if a buffer of $pH = 5.8$ is required?

$20 \ mL$ of $0.1 \ M$ acetic acid is mixed with $50 \ mL$ of potassium acetate. $K_a$ of acetic acid $= 1.8 \times 10^{-5}$ at $27^{\circ} C$. Calculate the concentration of potassium acetate if the $pH$ of the mixture is $4.8$. (in $M$)