Which buffer is present in human blood :-

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 not an acidic buffer?

$A$ litre of buffer solution contains $0.1 \ mol$ of each of $NH_3$ and $NH_4Cl$. On the addition of $0.02 \ mol$ of $HCl$ by dissolving gaseous $HCl$,the $pH$ of the solution is found to be $...... \times 10^{-3}$ (Nearest integer).
Given: $pK_b(NH_3) = 4.745$,$\log 2 = 0.301$,$\log 3 = 0.477$,$T = 298 \ K$.

The acidic and basic strength of buffer solutions remains constant because ...

The ionization constant $(K_a)$ of a certain weak acid is $10^{-4}$. What should be the $[salt]$ to $[acid]$ ratio if we have to prepare a buffer with $pH = 5$ using this acid and one of its salts?