$pH$ of $0.1 \ M$ solution of a weak acid $(HA)$ is $4.50$. It is neutralized with $NaOH$ solution to decrease the acid content to half. The $pH$ of the resulting solution is:

What is the concentration of $[H^+]$ in $mol/L$ in a mixed solution of $0.20 \ M \ CH_3COONa$ and $0.10 \ M \ CH_3COOH$? (Given: $K_a$ of $CH_3COOH = 1.8 \times 10^{-5}$)

For a buffer solution containing equal concentrations of $B^-$ and $HB$,where the $K_b$ of $B$ is $10^{-10}$,what is the $pH$ of the buffer solution?

The $pH$ of a simple sodium acetate buffer is given by $pH = pK_a + \log \frac{[Salt]}{[Acid]}$. $K_a$ of acetic acid $= 1.8 \times 10^{-5}$. If $[Salt] = [Acid] = 0.1 \, M$,the $pH$ of the solution would be about

$A$ buffer solution is prepared with a concentration of $0.30 \ M \ NH_3$ and $0.20 \ M \ NH_4^+$. If the equilibrium constant for $NH_3$ is $K_b = 1.8 \times 10^{-5}$,what will be the $pH$ of this solution?

$50 \, mL$ of $0.2 \, M$ ammonia solution is treated with $25 \, mL$ of $0.2 \, M$ $HCl$. If $pK_b$ of ammonia solution is $4.75$,the $pH$ of the mixture will be