Tartaric acid is a weak diprotic acid with ${\mathrm{K}}_1=1\times {10}^{-3}$ and ${\mathrm{K}}_2=4.6\times {10}^{-5}$.

Qualitatively describe the relative concentrations of ${\mathrm{H}}_2\mathrm{A}$, ${\mathrm{HA}}^{-}$, ${\mathrm{A}}^{2-}$ and ${\mathrm{H}}_3{\mathrm{O}}^{+}$ in a solution that is about $0.5 \mathrm{M}$ in tartaric acid.

Tartaric acid is a weak diprotic acid ${\mathrm{H}}_2\mathrm{A}$ with ${\mathrm{K}}_1=1\times {10}^{-3}$ and ${\mathrm{K}}_2=4.6\times {10}^{-5}.$ What is the ${\mathrm{A}}^{2-}$ concentration in $0.025 \mathrm{M} {\mathrm{H}}_2\mathrm{A}$?

If the answer is of type $\mathrm{y}\times {10}^{-5} \mathrm{M}$, report the value of $\mathrm{y}$ correct up to one places of decimal. Assume ${\mathrm{\alpha }}_2\ll {\mathrm{\alpha }}_1$.

The equilibrium equations and ${\mathrm{K}}_{\mathrm{a}}$ values for three reaction systems are given below.

$$\begin{gathered} {\mathrm{NH}}_4^{+} + {\mathrm{H}}_2\mathrm{O} \rightleftharpoons {\mathrm{H}}_3{\mathrm{O}}^{+}+ {\mathrm{NH}}_3; {\mathrm{K}}_{\mathrm{a}}= 5.6\times {10}^{-2} \\ {\mathrm{H}}_2{\mathrm{CO}}_{3 }+ {\mathrm{H}}_2\mathrm{O} \rightleftharpoons {\mathrm{H}}_3{\mathrm{O}}^{+}+ {\mathrm{HCO}}_3^{-}; {\mathrm{K}}_{\mathrm{a}}= 4.3\times {10}^{-7} \\ {\mathrm{H}}_2{\mathrm{PO}}_4^{-} + {\mathrm{H}}_2\mathrm{O} \rightleftharpoons {\mathrm{H}}_3{\mathrm{O}}^{+}+ {\mathrm{HPO}}_4^{2-}; {\mathrm{K}}_{\mathrm{a}}= 6.2\times {10}^{-8} \end{gathered}$$

The equilibrium equations and ${\mathrm{K}}_{\mathrm{a}}$ values for three reaction systems are given below

${\mathrm{H}}_2{\mathrm{CO}}_3 + {\mathrm{H}}_2\mathrm{O} \rightleftharpoons {\mathrm{H}}_3{\mathrm{O}}^{+} + {\mathrm{HCO}}_3^{-}; {\mathrm{K}}_{\mathrm{a}}=4.3\times {10}^{-7}$

Assuming that $50\%$ of the heat is useful, how many $\mathrm{kgs}$ of water, at $15°\mathrm{C}$, can be heated to $95°\mathrm{C}$ by burning $200 \mathrm{litres}$ of methane at $\mathrm{NTP}? {\mathrm{\Delta H}}_{\text{combustion }}\left({\mathrm{CH}}_4\right)$ $=211 \mathrm{kcal}/\mathrm{mole},\text{ specific heat of water }=1 \mathrm{kcal}/\mathrm{kg} \mathrm{K}.$

Answer after rounding off to the nearest integer value.

The rate of the reaction

${\mathrm{CH}}_3{\mathrm{CSNH}}_{2 }\left(\mathrm{aq}\right) + {\mathrm{H}}_2\mathrm{O}\stackrel{{\mathrm{H}}^{+}}{\to }{\mathrm{H}}_2\mathrm{S} \left(\mathrm{aq}\right) + {\mathrm{CH}}_3{\mathrm{CONH}}_{2 }\left(\mathrm{aq}\right)$

is given by the rate law:

$\text{ Rate }=\mathrm{k}\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right] \left[{\mathrm{CH}}_3{\mathrm{CSNH}}_2\right]$.

Consider $1 \mathrm{litre}$ of a solution that is $0.20 \mathrm{M}$ in ${\mathrm{CH}}_3{\mathrm{CSNH}}_2$ and $0.15 \mathrm{M}$ in $\mathrm{HCl}$ at $25°\mathrm{C}$.

State whether the rate of the reaction increases, decreases or remains the same when a $4 \mathrm{g}$ sample of $\mathrm{NaOH}$ is added to the solution.

The rate of the reaction

${\mathrm{CH}}_3{\mathrm{CSNH}}_2 \left(\mathrm{aq}\right) + {\mathrm{H}}_2\mathrm{O}\stackrel{{\mathrm{H}}^{+}}{\to }{\mathrm{H}}_2\mathrm{S} \left(\mathrm{aq}\right) + {\mathrm{CH}}_3{\mathrm{CONH}}_{2 }\left(\mathrm{aq}\right)$

is given by the rate law:

$\text{ Rate }=\mathrm{k}\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right] \left[{\mathrm{CH}}_3{\mathrm{CSNH}}_2\right]$.

Consider $1 \mathrm{litre}$ of a solution that is $0.20 \mathrm{M}$ in ${\mathrm{CH}}_3{\mathrm{CSNH}}_2$ and $0.15 \mathrm{M}$ in $\mathrm{HCl}$ at $25°\mathrm{C}$.

State whether the rate of the reaction increases, decreases or remains the same when $500 \mathrm{mL}$ of water is added to the solution.