$1.$ In an ideal solution, $\_\_\_\_\_\_\text{'}$s Law states that the partial vapor pressure of a component is directly proportional to its $\_\_\_\_$ in the mixture, and when combined with $\_\_\_\_\_\_\text{'}$s Law, it can be used to calculate the total pressure of a gas mixture.

$2.$ During the process of $\_\_\_\_\_\_$ vaporization, the composition of the vapor phase becomes richer in the more $\_\_\_\_$ component, whereas in $\_\_\_\_\_\_$ condensation, the liquid phase becomes enriched with the less volatile component.

$3.$ The concept of $\_\_\_\_\_\_$ volatility is crucial in distillation as it indicates how easily a mixture can be separated; it is defined as the ratio of vapor pressures of two components, $\_\_\_\_$ and $\_\_\_\_\_\_.$

$4.$ The McCabeThiele method is a graphical technique used to estimate the number of $\_\_\_\_\_\_$ stages in a distillation column by drawing the equilibrium line and operating lines, considering both the $\_\_\_\_$ and $\_\_\_\_\_\_$ reflux ratios.