Q1: When the feed to a distillation column is a saturated liquid, slope of the feed line is

ANS:C - infinity

In the context of a distillation column and its feed line on a T-x-y diagram, the concept of "slope infinity" doesn't directly apply. In mathematics, the slope of a line is defined as the ratio of the vertical change (rise) to the horizontal change (run) between any two points on the line. It represents the rate at which one variable changes with respect to another. However, in the case of a distillation column feed line on a T-x-y diagram, the slope of the feed line typically cannot be "infinity" because it implies a vertical line, which is not physically meaningful in this context. A T-x-y diagram typically represents temperature (T) on the x-axis and compositions (x and y) on the y-axis. The feed line represents the compositions of the liquid and vapor phases in equilibrium with each other at the feed temperature and pressure. When the feed is a saturated liquid, its composition remains constant along the feed line because no vaporization occurs until after the feed enters the column. Therefore, the feed line is a horizontal line on the T-x-y diagram, and its slope is effectively zero, not infinity. Therefore, "slope infinity" is not a relevant or meaningful concept in the context of a distillation column feed line on a T-x-y diagram.