Write characteristic and uses of weak base equilibrium constant ${K_b}$.
$(i)$ If the value of $K_{b}$ is more than base is more strong. $(ii)$ $K_{b}$ is a dimensionless quantity.
$(iii)$ With the help of $\mathrm{K}_{b}$, calculate $\left[\mathrm{OH}^{-}\right]$of weak base and then $pOH.$ $(iv)$ The ionization degree $(\alpha)$ of base can be calculated by value of $K_{b}$.
$(v)$ $\mathrm{pK}_{b}$ is calculate by using the value of $\mathrm{K}_{b^{*}}$
$\mathrm{pK}_{b}=-\log \left(\mathrm{K}_{b}\right)$
If $\mathrm{pK}_{b}$ value is more then base is less strong.
$\mathrm{K}_{b}$ | $1 \times 10^{-1}$ | $1 \times 10^{-2}$ | $1 \times 10^{-3}$ |
$\mathrm{pK}_{b}$ | $+1$ | $+2$ | $+3$ |
What are Diprotic and Triprotic acid ? differentiation eat .
A weak acid, $HA,$ has a $K_a$ of $1.00 \times 10^{-5}.$ If $0.100 \,mol$ of this acid is dissolved in one litreof water, the percentage of acid dissociated at equilibrium is closest to.....$\%$
Concentration $C{N^ - }$ in $0.1\,M\,HCN$ is $[{K_a} = 4 \times {10^{ - 10}}]$
${K_a}$ of $C{H_3}COOH$ is $1.76 \times {10^{ - 5}}$ at $298$ $K$ temperature. Calculate dissociation constant of its conjugate base.
When $100 \ mL$ of $1.0 \ M \ HCl$ was mixed with $100 \ mL$ of $1.0 \ M \ NaOH$ in an insulated beaker at constant pressure, a temperature increase of $5.7^{\circ} C$ was measured for the beaker and its contents (Expt. $1$). Because the enthalpy of neutralization of a strong acid with a strong base is a constant $\left(-57.0 \ kJ \ mol ^{-1}\right)$, this experiment could be used to measure the calorimeter constant. In a second experiment (Expt. $2$), $100 \ mL$ of $2.0 \ M$ acetic acid $\left(K_a=2.0 \times 10^{-5}\right)$ was mixed with $100 \ mL$ of $1.0 M \ NaOH$ (under identical conditions to Expt. $1$) where a temperature rise of $5.6^{\circ} C$ was measured.
(Consider heat capacity of all solutions as $4.2 J g ^{-1} K ^{-1}$ and density of all solutions as $1.0 \ g mL ^{-1}$ )
$1.$ Enthalpy of dissociation (in $kJ mol ^{-1}$ ) of acetic acid obtained from the Expt. $2$ is
$(A)$ $1.0$ $(B)$ $10.0$ $(C)$ $24.5$ $(D)$ $51.4$
$2.$ The $pH$ of the solution after Expt. $2$ is
$(A)$ $2.8$ $(B)$ $4.7$ $(C)$ $5.0$ $(D)$ $7.0$
Give the answer question $1$ and $2.$