Final answer:
To estimate the percent composition of the starting MeOH:Water solution using the fractional distillation plot, find the point on the plot where the distillation curve intersects with the MeOH and Water axes. The x-coordinate of this point represents the percent composition of MeOH in the solution, while the y-coordinate represents the percent composition of Water.
Step-by-step explanation:
To estimate the percent composition of the starting MeOH:Water solution using the fractional distillation plot, you need to find the point on the plot where the distillation curve intersects with the MeOH and Water axes. The x-coordinate of this point represents the percent composition of MeOH in the solution, while the y-coordinate represents the percent composition of Water. You can draw vertical and horizontal lines from this point to the x-axis and y-axis, respectively, to visually illustrate the percent compositions.