A weak base $\mathrm{BOH}$ was titrated against a strong acid. The $\mathrm{pH}$ at one-fourth equivalence point was $9.24 .$ Enough strong base was now added $(6 \mathrm{m}.\mathrm{e}.)$ to completely convert the salt. The total volume was $50 \mathrm{mL}$. Find the $\mathrm{pH}$ at this point.

Answer correct up to one place of decimal.

Calculate the equilibrium constant for the reaction $2{\mathrm{Fe}}^{3+}+3{\mathrm{I}}^{-}\rightleftharpoons 2{\mathrm{Fe}}^{2+}+{\mathrm{I}}_3^{-}$. The standard reduction potentials in acidic-medium conditions are $0.77$and $0.54 \mathrm{V}$ respectively for ${\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}$ and ${\mathrm{I}}_3^{-}/{\mathrm{I}}^{-}$ couples.

If the answer is of type $\mathrm{y}\times {10}^7$, report the value of $\mathrm{y}$ correct up to the nearest integer.

The degree of dissociation is $0.4$at $400 \mathrm{K}$ and $1 \mathrm{atm}$ for the gaseous reaction

${\mathrm{PCl}}_5\rightleftharpoons {\mathrm{PCl}}_3+{\mathrm{Cl}}_2$

Assuming ideal behaviour of all the gases, calculate the density of equilibrium mixture $\left(\text{in} \mathrm{g}/\mathrm{L}\right)$ at $400 \mathrm{K}$ and $1 \mathrm{atm}$.

Answer correct up to three places of decimals.

Given: $Ag{\left({\mathrm{NH}}_3\right)}_2^{+}\rightleftharpoons {\mathrm{Ag}}^{+}+2{\mathrm{NH}}_3, {\mathrm{K}}_{\mathrm{c}}=6.2\times {10}^{-8}$ and ${\mathrm{K}}_{\mathrm{sp}}$ of $\mathrm{AgCl}=1.8\times {10}^{-10}$ at $298 \mathrm{K}.$ Calculate the concentration of the complex in $1.0 \mathrm{M}$ aqueous ammonia.

A solution of a nonvolatile solute in water freezes at $-0.30°\mathrm{C}$. The vapour pressure of pure water at $298 \mathrm{K}$ is $23.51 \mathrm{mm} \mathrm{Hg}$ and ${\mathrm{K}}_{\mathrm{f}}$ for water is $1.86 \mathrm{degree}/\mathrm{molal}$. Calculate the magnitude of change in vapour pressure of this solution $\left(\mathrm{in} \mathrm{mmHg}\right)$ at $298 \mathrm{K}$.

Give answer after multiplying with 100 and rounding off to the nearest integer value.

For the reaction, ${\mathrm{N}}_2{\mathrm{O}}_5\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{NO}}_2\left(\mathrm{g}\right)+0.5{\mathrm{O}}_2\left(\mathrm{g}\right),$ calculate the mole fraction of ${\mathrm{N}}_2{\mathrm{O}}_5\left(\mathrm{g}\right)$ decomposed at a constant volume and temperature, if the initial pressure is $600 \mathrm{mmHg}$ and the pressure at any time is $960 \mathrm{mmHg}$. Assume ideal gas behaviour.

Find the solubility product of a saturated solution of ${\mathrm{Ag}}_2{\mathrm{CrO}}_4$ in water at $298 \mathrm{K}$ if the emf of the cell $\mathrm{Ag}\left|{\mathrm{Ag}}^{+}\left(\text{satd. }{\mathrm{Ag}}_2{\mathrm{CrO}}_4\text{ soln. }\right)\right|\left|{\mathrm{Ag}}^{+}\right(0.1 \mathrm{M}\left)\right|\mathrm{Ag}$ is $0.164 \mathrm{V}$ at $298 \mathrm{K}$. If solubility product is $\mathrm{a}\times {10}^{-12}$, report $\text{'}\mathrm{a}\text{'}.$