Given: \(K_{\mathrm{b}}\) (dimethylamine) \(=7.4 \times 10^{-4} \mathrm{M}\). A buffer is made by mixing…
Given: \(K_{\mathrm{b}}\) (dimethylamine) \(=7.4 \times 10^{-4} \mathrm{M}\). A buffer is made by mixing \(\left(\mathrm{CH}_{3}ight)_{2} \mathrm{NH}\) and \(\left(\mathrm{CH}_{3}ight)_{2} \mathrm{NH}_{2} \mathrm{Cl}\). The range of buffer to which this buffer can be used is
\(2.13\) to \(4.13\)
\(6.13\) to \(8.13\)
\(8.13\) to \(10.13\)
\(9.87\) to \(11.87\)
Solution
\(\mathrm{p} K_{\mathrm{b}}^{\circ}=-\log \left(7.4 \times 10^{-4} \mathrm{M}ight)=3.13\)
Buffer range is \(14-\mathrm{p} K_{\mathrm{b}}-1\) to \(14-\mathrm{p} K_{\mathrm{b}}+1\), i.e. \(9.87\) to \(11.87\)
^