$A$ buffer solution is prepared by mixing $0.2 \ M \ NH_4OH$ and $1 \ M \ NH_4Cl$. What is the $pH$ value of the buffer solution? (Given $pK_b = 4.744$)

The $K_a$ of $CH_3COOH$ is $1.8 \times 10^{-5}$. How many grams of $CH_3COONa$ are required in $0.1 \ M \ CH_3COOH$ to form a solution having $pH = 4.0$? (Molecular mass of $CH_3COONa = 82 \ g \ mol^{-1}$)

Which of the following mixtures forms an acidic buffer?

If the $pH$ of a mixture of $10 \, mL$ of $0.1 \, M \, NH_4OH$ and $10 \, mL$ of $1 \, M \, NH_4Cl$ solution is $8$,the $pK_b$ value of $NH_4OH$ is then closest to

In which of the following combinations is buffer action expected?
$1$. $NH_3 + NH_4Cl$
$2$. $HCl + NaCl$
$3$. $NH_3 + HCl$ in $2 : 1$ mole ratio
Select the correct answer using the code given below.

When $30 \ mL$ of $0.2 \ M \ NH_4OH$ is added to $30 \ mL$ of $2 \ M \ NH_4Cl$ solution. If the $pH$ of the buffer formed is $8.2$,what is the $pK_b$ of $NH_4OH$?