The second stage feed water temperature and shell absolute pressure in a multistage, flash type, distilling plant is __________.

Correct Answer: Option B — lower than the first stage feed water temperature and absolute shell pressure

Flash-type distilling plants operate on a pressure-temperature gradient across stages. As the brine flashes into vapor, the pressure drops in subsequent stages to facilitate further evaporation. Consequently, the second stage must operate at a lower absolute pressure and lower feed water temperature than the first stage to maintain efficient distillation.