$8\mathrm{.}4-5.$ Boiling$-$Point Rise of NaOH Solutions. Determine the boiling temperature of the solution and the boiling$-$point rise for the following $($a$)$ A $30\%$ NaOH solution boiling in an evaporator at a pressure of $172\mathrm{.}4$ kPa $(25$ psia$)($b$)$ A $60\%$ NaOH solution boiling in an evaporator at a pressure of $3\mathrm{.}45$ kPa $(0\mathrm{.}50$ psia$)$ cases Ans. $($a$)$ Boiling point $130\mathrm{.}6\backslash$deg C$,$ boiling point rise$=15\backslash$deg C