a
આપેલ  \(w = 174.5 \times 10^{-3}, W = 78 g, m = 8 \times 32 = 256\)

( \(\because \) અષ્ટપરમાણ્વીય, \(K^{'}_b\) \(= 5.2\))

\(\because \,\,\Delta T\,\, = \,\,\frac{{1000{K_b}w}}{{mW}}\)

\( = \,\,\frac{{1000\,\, \times \,\,5.2\,\, \times \,\,174.5\,\, \times \,{{10}^{ - 3}}}}{{78\,\, \times \,\,256}}\)  \( = \,\,0.045\)  

\(\therefore \,\,B{r_2}\)  દ્રાવણ નું ઉત્લકન  બિદુ

\( = \,\,332.15\,\, + \,\,\Delta {T_b}\,\, = \,\,332.15\,\, + \;\,0.045\,\, = \,\,332.195\,\,K\)