$A$ buffer that is a mixture of acetic acid $(K_a = 2 \times 10^{-5})$ and potassium acetate has $pH = 5.18$. The $\frac{[CH_3COO^{-}]}{[CH_3COOH]}$ ratio in this buffer is approximately:

What is the $pH$ of a buffer solution formed by mixing $0.01 \ M$ acetic acid and $0.05 \ M$ sodium acetate $(pK_a = 4.7447)$?

Give the importance of buffer solution.

$A$ student needs to prepare a buffer solution of propanoic acid and its sodium salt with $pH$ $4$. The ratio of $\frac{[CH_{3}CH_{2}COO^{-}]}{[CH_{3}CH_{2}COOH]}$ required to make the buffer is .....
Given: $K_{a}(CH_{3}CH_{2}COOH) = 1.3 \times 10^{-5}$

$A$ buffer solution is formed by a weak acid and its salt with a strong base,or a weak base and its salt with a strong acid. In which of the following pairs is this characteristic found?

$A$ weak acid,$HA$,is found to be $10\%$ ionized in $0.01\ M$ aqueous solution. Calculate the $pH$ of a solution which is $0.1\ M$ in $HA$ and $0.05\ M$ in $NaA$.