Embibe Experts Solutions for Chapter: Equilibrium, Exercise 5: EXERCISE-IV (Assertion & Reason)

$\mathrm{Assertion}:$$\mathrm{pH}$ of a buffer changes with temperature.

$\mathrm{Reason}:$lonic product of water $\left({\mathrm{K}}_{\mathrm{w}}\right)$ changes with temperature.

$\mathrm{Assertion}:$${\mathrm{H}}_2\mathrm{O}$ is amphoteric in nature.
$\mathrm{Reason}:$${\mathrm{H}}_2\mathrm{O}$ can accept a proton to form ${\mathrm{H}}_3{\mathrm{O}}^{+}$ ion and can donate a proton to form ${\mathrm{OH}}^{-}$ ion.

Assertion: All Arrhenius acids are also Bronsted acids.

Reason: All Bronsted bases are also Lewis bases.

$\mathrm{Assertion}:$ The buffer solution has a capacity to resist the change in $\mathrm{pH}$ value on addition of small amount of acid or base to it.

$\mathrm{Reason}:$ $\mathrm{pH}$ value of buffer solution does not change on dilution or on keeping for long.

$\mathrm{Assertion}:$ Solubility of sparingly soluble salt increases with increase in temperature.

$\mathrm{Reason}:$ Enthalpy of solution is negative for all salts.

$\mathrm{Assertion}:$ $\mathrm{HCl}$ is titrated with $\mathrm{NaOH}$ using phenolphthalein as indicator, pink colour appears in solution when ${\mathrm{OH}}^{-}$ ion is present in excess in solution.

$\mathrm{Reason}:$ At end point, both reacting species, neutralises each other.

$\mathrm{Assertion}:$ ${\mathrm{Na}}_2{\mathrm{SO}}_3$ is alkaline towards litmus.
$\mathrm{Reason}:$ ${\mathrm{H}}_2{\mathrm{SO}}_3$ is formed due to hydrolysis.

The oxidation state of metal in Iron in ${\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]}^{3-}$ is