a
\(\Delta T_b\) = મોલારીટી \(\times\) \(K_b\)

\(\Delta {T_b}\,\, = \,\,\frac{w}{{m\,\, \times \,\,W}}\,\, \times \,\,1000\,\, \times \,\,{K_b},\)

\({K_b}\,\, = \,\,\frac{{\Delta {T_b}\, \times \,\,m\,\, \times \,\,W}}{{1000\,\, \times \,\,w}}\)

\(\Delta \,\,{T_b}\,\, = \,\,0.1\,^oC\,,\,\,m\,\, = \,\,180,\,\,\)

\(W\,\, = \,\,100\,,\,w\,\, = \,\,1.8\,\)

\({K_b}\,\, = \,\,\frac{{180\,\, \times \,\,0.1\,\, \times \,\,100}}{{1000\,\, \times \,1.8}}\,\, = \,\,1.0\)