A buffer solution is prepared by mixing 20 mL of 0.1 M CH$_3$COOH and 30 mL of 0.2 M CH$_3$COONa. To this mixture, 1 mL of 1 M NaOH is added. The pH change of the buffer is closest to (pK$_a$ of CH$_3$COOH = 4.74):

$50\;mL$ of $2\;N$ acetic mixed with $10\;mL$ of $1\;N$ sodium acetate solution will have an approximate ${\rm{pH}}$ of $\left( {{K_a} = {{10}^{ - 5}}} \right):$

A buffer solution with pH 9 is to be prepared using NH$_4$OH (K$_b$= 1.8 x 10$^{-5}$) and NH$_4$Cl. What should be the ratio of [NH$_4$Cl]/[NH$_4$OH]?

In a mixture of ${\rm{C}}{{\rm{H}}_3}{\rm{COOH}}$ and ${\rm{C}}{{\rm{H}}_3}{\rm{COONa}},$ the ratio of salt to acid concentration is increased by ten folds. The $pH$ of the solution will increase by:

Which of the following is an example of a buffer solution?

${50\% }$ neutralization of a solution of formic acid $\left( {{K_a} = 2 imes {{10}^{ - 4}}} \right)$ with ${\rm{NaOH}}$ would result in a solution having a hydrogen ion concentration of:

A buffer solution contains 0.2 M formic acid (HCOOH) and 0.3 M sodium formate (HCOONa). The $K_a$ of formic acid is $1.8 imes 10^{-4}$. What is the pH of this buffer solution?

Which of the following combinations will form a basic buffer solution?

pH of 0.2 M aqueous solution of sodium benzoate will be ($P{K_a}$ of benzoic acid = 4.2)

The ${\rm{p}}{K_a}$ of ${{\rm{HCN}}}$ is 9.30. The ${\rm{pH}}$ of a solution prepared by mixing 2.5 moles of ${{\rm{KCN}}}$ and 2.5 moles of ${{\rm{KCN}}}$ and 2.5 moles of ${{\rm{HCN}}}$ in water and making up the total volume of 500 mL, is

Buffer solutions have constant acidity and alkalinity because: