$\mathrm{pH}$ of a solution obtained by mixing equal volumes of $0.1 \mathrm{M}$ triethylamine $\left({\mathrm{K}}_{\mathrm{b}}=6.4\times {10}^{-5}\right)$ and $\frac{4}{45} \mathrm{M}$ ${\mathrm{NH}}_4\mathrm{OH} \left({\mathrm{K}}_{\mathrm{b}}=1.8\times {10}^{-5}\right)$ will be:

In aqueous solution, the ionization constants for carbonic acid are ${\mathrm{K}}_1=4.2\times {10}^{-7}$ and ${\mathrm{K}}_2=4.8\times {10}^{-11}$. Select the correct statement for a saturated $0.034 \mathrm{M}$solution of the carbonic acid.

$50 \mathrm{mL}$ of $0.05 \mathrm{M}$ Propane$-$ $1,2$ $-$diamine solution is titrated with $0.1 \mathrm{M} \mathrm{HCl}$ solution at $25°\mathrm{C}$. Determine the $\mathrm{pH}$of solutions obtained by adding $25\mathrm{ml}$ volumes of $\mathrm{HCl}$ solution:

Given: ${\mathrm{pK}}_{\mathrm{b}1}$ and ${\mathrm{pK}}_{{\mathrm{b}}_2}$ of weak base are $4.18$and $7.39$respectively.

$50 \mathrm{mL}$ of $0.05 \mathrm{M}$ Propane $-$$1,2$ $-$diamine solution is titrated with $0.1 \mathrm{M} \mathrm{HCl}$ solution at $25°\mathrm{C}$. Determine the $\mathrm{pH}$of solutions obtained by adding $30 \mathrm{mL}$volumes of $\mathrm{HCl}$ solution:

Given: ${\mathrm{pK}}_{{\mathrm{b}}_1}$ and ${\mathrm{pK}}_{{\mathrm{b}}_2}$ of weak base are $4.18$and $7.39$respectively.

$500 \mathrm{ml}$ of $0.2 \mathrm{M}$ an aqueous solution of acetic acid is mixed with $500 \mathrm{mL}$ of $0.2 \mathrm{M} \mathrm{HCl}$ at $25°\mathrm{C}$.

If $6 \mathrm{g}$of $\mathrm{NaOH}$is added to the above solution, determine the final $\mathrm{pH}$. Assume there is no change in the volume on mixing. ${\mathrm{K}}_{\mathrm{a}}$ of acetic acid is $1.75\times {10}^{-5}$.